Klacid 250mg Film-coated Tablets
*Company:
Mylan IRE Healthcare LtdStatus:
No Recent UpdateLegal Category:
Product subject to medical prescription which may not be renewed (A)Active Ingredient(s):
*Additional information is available within the SPC or upon request to the company
Updated on 12 August 2024
File name
ie-spc-Klacid 250mg Tablets-pr3455125-MIC breakpoints-clean.pdf
Reasons for updating
- Change to section 5.1 - Pharmacodynamic properties
- Change to section 10 - Date of revision of the text
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Updated on 16 April 2024
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ie-pl-Klacid 250mg Forte 500mg Tablets-pr3373222-PRAC update-clean.pdf
Reasons for updating
- Change to section 2 - what you need to know - contraindications
- Change to section 2 - what you need to know - warnings and precautions
Updated on 16 April 2024
File name
ie-spc-Klacid 250mg Tablets-pr3373222-PRAC update-clean.pdf
Reasons for updating
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 27 November 2023
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ie-pl-Klacid 250mg 500mg Tablets-pr3083480-maht-clean.pdf
Reasons for updating
- Change to section 6 - marketing authorisation holder
Updated on 27 November 2023
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ie-pl-Klacid 250mg 500mg Tablets-pr3083480-maht-clean.pdf
Reasons for updating
- Change to section 6 - marketing authorisation holder
Updated on 27 November 2023
File name
ie-pl-Klacid 250mg 500mg Tablets-pr3083480-maht-clean.pdf
Reasons for updating
- Change to section 6 - marketing authorisation holder
Updated on 27 November 2023
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ie-spc-Klacid 250mg Tablets-pr3083480-maht-clean.pdf
Reasons for updating
- Change to section 7 - Marketing authorisation holder
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Updated on 27 November 2023
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ie-spc-Klacid 250mg Tablets-pr3083480-maht-clean.pdf
Reasons for updating
- Change to section 7 - Marketing authorisation holder
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 27 November 2023
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ie-spc-Klacid 250mg Tablets-pr3083480-maht-clean.pdf
Reasons for updating
- Change to section 7 - Marketing authorisation holder
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 27 April 2021
File name
IE-SmPC-Klacid 250mg Tablets-22Apr2021-CRN00C7WV-clean.pdf
Reasons for updating
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.6 - Pregnancy and lactation
- Change to section 4.8 - Undesirable effects
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 27 April 2021
File name
IE-PIL-Klacid 250mg 500mg Tablets-22Apr202-CRN00C7WV1-clean.pdf
Reasons for updating
- Change to section 2 - what you need to know - contraindications
- Change to section 2 - what you need to know - warnings and precautions
- Change to section 2 - interactions with other medicines, food or drink
- Change to section 4 - possible side effects
- Change to section 6 - date of revision
Updated on 07 May 2019
File name
IE-PIL-Klacid 250mg 500mg Tablets-18Apr2019-CRN008JWH-clean.pdf
Reasons for updating
- Change to section 2 - what you need to know - contraindications
- Change to section 2 - interactions with other medicines, food or drink
- Change to section 6 - date of revision
Updated on 03 May 2019
File name
IE-SmPC-Klacid 250mg Tablets-18Apr2019-CRN008JWH-clean.pdf
Reasons for updating
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 14 January 2019
File name
IE-PIL-Klacid 250mg 500mg Tablets-11Jan2019-CRN008JX3-clean.pdf
Reasons for updating
- Change to section 4 - possible side effects
- Change to section 6 - what the product contains
- Change to section 6 - date of revision
Updated on 14 January 2019
File name
IE-SmPC-Klacid 250mg Tablets-11Jan2019-CRN008JX3-clean.pdf
Reasons for updating
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.8 - Undesirable effects
- Change to section 6.1 - List of excipients
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 10 January 2019
File name
IE-SmPC-Klacid 250mg Tablets-04Jan2019-CRN008K12-clean.pdf
Reasons for updating
- Change to section 4.6 - Pregnancy and lactation
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 26 November 2018
File name
IE-PIL-Klacid 250mg 500mg Tablets-23Nov2018-CRN008LLM-clean.pdf
Reasons for updating
- Change to section 2 - interactions with other medicines, food or drink
- Change to section 2 - excipient warnings
- Change to section 6 - date of revision
Updated on 26 November 2018
File name
IE-SmPC-Klacid 250mg Tablets-23Nov2018-CRN008LLM-clean.pdf
Reasons for updating
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 29 May 2018
File name
Upload- SmPC-Klacid 250mg Tablets-21May2018-CRN2204978-clean.docx
Reasons for updating
- Change to section 4.4 - Special warnings and precautions for use
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 09 November 2017
File name
PIL_10665_437.pdf
Reasons for updating
- New PIL for new product
Updated on 09 November 2017
Reasons for updating
- Change to section 2 - use in children and adolescents
- Change to section 2 - interactions with other medicines, food or drink
- Change to section 2 - driving and using machines
- Change to section 3 - dose and frequency
- Change to section 3 - duration of treatment
- Change to section 5 - how to store or dispose
- Change to section 6 - what the product contains
- Change to section 6 - what the product looks like and pack contents
- Change to section 6 - date of revision
Updated on 03 May 2017
Reasons for updating
- New SPC for new product
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 03 May 2017
Reasons for updating
- Change to section 7 - Marketing authorisation holder
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Free text change information supplied by the pharmaceutical company
Mylan IRE Healthcare Limited
Unit 35/36
Grange Parade
Baldoyle Industrial Estate
Dublin 13
Ireland
4051 Kingswood Drive
Citywest Business Campus
Dublin 24
Ireland
10. DATE OF REVISION OF THE TEXT
Updated on 28 April 2017
Reasons for updating
- Change to section 6 - marketing authorisation holder
- Change to section 6 - date of revision
Updated on 04 July 2016
Reasons for updating
- Change to warnings or special precautions for use
- Change of contraindications
Updated on 07 June 2016
Reasons for updating
- Change to section 4.2 - Posology and method of administration
- Change to section 4.3 - Contraindications
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.8 - Undesirable effects
Legal category:Product subject to medical prescription which may not be renewed (A)
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4.2 Posology and Method of Administration
- correction of dosage for mycobacterial infections
4.3 Contraindications – addition of cross references to other sections of SPC
4.5 Interaction with other medicinal products and other forms of interaction
- addition of cross reference to other section of SPC
4.8 Undesirable effects
– correction of footnotes of the AE table
- deletion of text regarding insufficient data for IV dosing in patients less than 18 yearsUpdated on 03 June 2016
Reasons for updating
- Change to side-effects
- Change to drug interactions
- Change to dosage and administration
Updated on 18 January 2016
Reasons for updating
- Change to section 4.1 - Therapeutic indications
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.8 - Undesirable effects
Legal category:Product subject to medical prescription which may not be renewed (A)
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- In section 4.1 - addition of notes re Sensitivity Testing for certain indications
- In section 4.3 - update regarding QT prolongation
- In section 4.4 - update regarding oromucosal midazolam, deletion of warning for ototoxic drugs (aminoglycoside), update regarding QT prolongation, deletion of Henoch-Schonlein purpura,
- In section 4.5 - addition of interaction re oral midazolam, addition of interaction with quetiapine, deletion of interation with aminoglycosides, update of colchicine interaction
- In section 4.8 - deletion of ADR "screaming", addition of "ventricular fibrillation"
Updated on 18 January 2016
Reasons for updating
- Change to warnings or special precautions for use
- Change of contraindications
- Change to side-effects
- Change to drug interactions
Updated on 07 July 2015
Reasons for updating
- Change to packaging
Updated on 25 June 2015
Reasons for updating
- Change to storage instructions
Updated on 15 June 2015
Reasons for updating
- Change to section 3 - Pharmaceutical form
Legal category:Product subject to medical prescription which may not be renewed (A)
Free text change information supplied by the pharmaceutical company
Updated on 10 June 2015
Reasons for updating
- Change of manufacturer
- Change to appearance of the medicine
Updated on 20 April 2015
Reasons for updating
- Change to marketing authorisation holder
Updated on 09 April 2015
Reasons for updating
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.6 - Pregnancy and lactation
- Change to section 4.8 - Undesirable effects
- Change to Section 4.8 – Undesirable effects - how to report a side effect
- Change to section 7 - Marketing authorisation holder
- Change to section 8 - MA number
Legal category:Product subject to medical prescription which may not be renewed (A)
Free text change information supplied by the pharmaceutical company
- Section 4.3: Addition of contraindication for ticagrelor and ranolazine. Update of contraindication for colchicine.
- Section 4.4: Deletion of 'exacerbation of symptoms of myasthenia gravis. Update of information relating to colchicine, QT prolongation, statins and oral hypoglycaemic agents/insulin.
- Section 4.5: Addition of information regarding HMG-CoA Reductase Inhibitors (statins), dispyramide, oral hypoglycaemic agents/insulin, aminoglycosides, calcium channel blockers. Deletion of information regarding verapamil.
- Section 4.6: Update of pregancy information.
- Section 4.8: Deletion of erythrasma, hypoglycaemia, Henoch-Schonlein purpura. Addition of angioedema. Update of sections 'Description of selected adverse reactions' and 'Paediatric populations' and 'Immunocompromised patients'. Addition of text for 'Reporting of suspected adverse reactions'
- Section 7: Update of Marketing Authorisation Holder from Abbott Laboratories Ireland Limited to BGP Products Ireland Limited
- Section 8: Update of PA number
Updated on 31 March 2015
Reasons for updating
- Change to warnings or special precautions for use
- Change of contraindications
- Change to side-effects
- Change to drug interactions
- Addition of information on reporting a side effect.
Updated on 20 February 2015
Reasons for updating
- Change to section 2 - Qualitative and quantitative composition
- Change to section 4.2 - Posology and method of administration
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.8 - Undesirable effects
- Change to section 5.1 - Pharmacodynamic properties
- Change to section 6.4 - Special precautions for storage
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Section 4.2: Removal of information regarding Dual Therapy
Section 4.3: Addition of contraindication for concomitant administration with oral midazolam
Section 4.4: Clarification regarding intravenous midazolam
Section 4.5: Minor amendments
Section 4.8: Addition of mania
Section 5.1: Addition of pharmacotherapeutic group, ATC code and other information
Section 6.4: Clarification that instruction to "Store in the original package" is "in order to protect from light"
Updated on 19 February 2015
Reasons for updating
- Change to warnings or special precautions for use
- Change of contraindications
- Change to storage instructions
- Change to side-effects
- Change to drug interactions
- Change to dosage and administration
Updated on 20 February 2013
Reasons for updating
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.8 - Undesirable effects
Legal category:Product subject to medical prescription which may not be renewed (A)
Free text change information supplied by the pharmaceutical company
- Section 4.4: Update of warning regarding statins
- Section 4.8: Addition of paraesthesia
- Other minor corrections to text throughout the SPC
Updated on 18 February 2013
Reasons for updating
- Change to warnings or special precautions for use
- Change of contraindications
- Change to side-effects
- Change to drug interactions
Updated on 20 August 2012
Reasons for updating
- Change to section 4.2 - Posology and method of administration
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.6 - Pregnancy and lactation
- Change to section 4.8 - Undesirable effects
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
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4.2 Posology and method of administration
The following text has been deleted:
Use of clarithromycin tablets is not recommended for children under 12 years.
The following text has been added:
The use of clarithromycin tablets has not been studied in children under 12 years.
4.3 Contraindications
The following sentences have been added:
Concomitant administration of clarithromycin with lovastatin or simvastatin is also contraindicated.
Colchicine is contraindicated in patients with renal or hepatic impairment who are taking P-glycoprotein or a strong CYP3A4 inhibitor.
4.4 Special warnings and precautions for use
The following paragraph has been added:
Hepatic dysfunction, including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, has been reported with clarithromycin. This hepatic dysfunction may be severe and is usually reversible. In some instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications. Discontinue clarithromycin immediately if signs and symptoms of hepatitis occur, such as anorexia, jaundice, dark urine, pruritus, or tender abdomen.
The following text has been deleted:
coronary artery disease, severe cardiac insufficiency, hypomagnesemia, bradycardia (<50 bpm), or when co-administered with other medicinal products associated with
The following text has been added:
a medical condition associated with an increased tendency toward QT prolongation and torsades de pointes.
The following text has been deleted:
(see section 4.5). Clarithromycin must not be used in patients with congenital or documented acquired QT prolongation or history of ventricular arrhythmia (see section 4.3).
DRESS and Henoch-Schonlein purpura have been added as hypersensitivity reactions.
4.5 Interaction with other medicinal products and other forms of interaction
The following paragraph has been added:
Etravirine
Clarithromycin exposure was decreased by etravirine; however, concentrations of the active metabolite, 14-OH-clarithromycin, were increased. Because 14-OH-clarithromycin has reduced activity against Mycobacterium avium complex (MAC), overall activity against this pathogen may be altered; therefore alternatives to clarithromycin should be considered for the treatment of MAC.
4.6 Pregnancy and lactation
The title ‘Pregnancy’ has been added.
The following text has been deleted:
Breast-feeding of infants
Based on variable results obtained from studies in mice, rats, rabbits and monkeys, the possibility of adverse effects on embryofoetal development cannot be excluded.
The following text has been added:
Lactation
The safety of clarithromycin use during breast-feeding of infants has not been established.
b. Tabulated summary of adverse reactions
Henoch-Schonlein purpura has been added under Not Known for Skin and subcutaneous tissue disorders.
The following text has been added under the adverse reactions table:
* Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Patient exposure is estimated to be greater than 1 billion patient treatment days for clarithromycin.
** In some of the reports of rhabdomyolysis, clarithromycin was administered concomitantly with statins, fibrates, colchicine or allopurinol.
c. Description of selected adverse reactions
The following text has been deleted:
Injection site phlebitis, injection site pain, vessel puncture site pain, and injection site inflammation are specific to the clarithromycin intravenous formulation.
In very rare instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications (see section 4.4).
A special attention to diarrhoea should be paid as Clostridium difficile-associated diarrhoea (CDAD) has been reported with use of nearly all antibacterial agents including clarithromycin, and may range in severity from mild diarrhoea to fatal colitis. (see section 4.4)
In the event of severe acute hypersensitivity reactions, such as anaphylaxis, Stevens-Johnson Syndrome and toxic epidermal necrolysis, clarithromycin therapy should be discontinued immediately and appropriate treatment should be urgently initiated (see section 4.4).
As with other macrolides, QT prolongation, ventricular tachycardia, and torsade de pointes have rarely been reported with clarithromycin (see section 4.4 and 4.5).
Pseudomembranous colitis has been reported with nearly all antibacterial agents, including clarithromycin, and may range in severity from mild to life threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhoea subsequent to the administration of antibacterial agents (see section 4.4).
In some of the reports of rhabdomyolysis, clarithromycin was administered concomitantly with statins, fibrates, colchicine or allopurinol (see section 4.3 and 4.4).
Injection site phlebitis, injection site pain, vessel puncture site pain, and injection site inflammation are specific to the clarithromycin intravenous formulation.
In very rare instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications (see section 4.4).
A special attention to diarrhoea should be paid as Clostridium difficile-associated diarrhoea (CDAD) has been reported with use of nearly all antibacterial agents including clarithromycin, and may range in severity from mild diarrhoea to fatal colitis. (see section 4.4)
In the event of severe acute hypersensitivity reactions, such as anaphylaxis, Stevens-Johnson Syndrome and toxic epidermal necrolysis, clarithromycin therapy should be discontinued immediately and appropriate treatment should be urgently initiated (see section 4.4).
As with other macrolides, QT prolongation, ventricular tachycardia, and torsade de pointes have rarely been reported with clarithromycin (see section 4.4 and 4.5).
Pseudomembranous colitis has been reported with nearly all antibacterial agents, including clarithromycin, and may range in severity from mild to life threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhoea subsequent to the administration of antibacterial agents (see section 4.4).
In some of the reports of rhabdomyolysis, clarithromycin was administered concomitantly with statins, fibrates, colchicine or allopurinol (see section 4.3 and 4.4).
The following text has been deleted:
There have been rare reports of hypoglycemia, some of which have occurred in patients on concomitant oral hypoglycemic agents or insulin (see section 4.4 and 4.5).
There have been post-marketing reports of drug interactions and central nervous system (CNS) effects (e.g. somnolence and confusion) with the concomitant use of clarithromycin and triazolam. Monitoring the patient for increased CNS pharmacological effects is suggested (see section 4.5).
There is a risk of serious haemorrhage and significant elevations in INR and prothrombin time when clarithromycin is co-administered with warfarin. INR and prothrombin times should be frequently monitored while patients are receiving clarithromycin and oral anticoagulants concurrently (see section 4.4 and 4.5).
d. Paediatric populations
The following text has been deleted:
Special population: Adverse Reactions in Immunocompromised Patients (see section e)
2000mg
The incidences were comparable for patients treated with 100mg and 200mg, but were generally about 3 to 4 times as frequent for those patients who received total daily doses of 4000mg of clarithromycin.
Slightly higher incidences of abnormal values were noted for patients who received 4000mg daily for all parameters except White Blood Cell.
10. Date of revision of the text
The date has been updated to July 2012.
Updated on 15 August 2012
Reasons for updating
- Change to warnings or special precautions for use
- Change to side-effects
- Change to drug interactions
- Change to date of revision
Updated on 18 August 2011
Reasons for updating
- Change due to user-testing of patient information
Updated on 17 February 2011
Reasons for updating
- Change to section 4.1 - Therapeutic indications
- Change to section 4.2 - Posology and method of administration
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.6 - Pregnancy and lactation
- Change to section 4.7 - Effects on ability to drive and use machines
- Change to section 4.8 - Undesirable effects
- Change to section 4.9 - Overdose
Legal category:Product subject to medical prescription which may not be renewed (A)
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Update of the SPC sections 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8 & 4.9
Updated on 13 October 2010
Reasons for updating
- Change to section 1 - Name of medicinal product
- Change to section 2 - Qualitative and quantitative composition
- Change to section 6.1 - List of excipients
Legal category:Product subject to medical prescription which may not be renewed (A)
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Section 2 - Add text 'For a full list of excipients, see section 6.1'
Section 6.1 - Update list of excipients
Updated on 24 August 2010
Reasons for updating
- Change to further information section
- Change to product name
Updated on 09 November 2009
Reasons for updating
- Change to section 4.3 - Contraindications
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.8 - Undesirable effects
- Change to section 4.9 - Overdose
- Change to section 5.1 - Pharmacodynamic properties
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4.3 Contraindications
Use in patients with known hypersensitivity to macrolide antibiotic drugs.
Use in patients with serious impairment of hepatic function.
Clarithromycin and ergot derivatives should not be co-administered.
Concomitant administration of clarithromycin and any of the following drugs is contraindicated: astemizole, cisapride, pimozide and terfenadine. Elevated cisapride, pimozide and terfenadine levels have been reported in patients receiving either of these drugs and clarithromycin concomitantly. This may result in QT prolongation and cardiac arrhythmias including ventricular fibrillation and torsade de pointes. Similar effects have been observed with concomitant administration of astemizole and other macrolides.
4.4 Special warnings and precautions for use
The physician should not prescribe clarithromycin to pregnant women without carefully weighing the benefits against risk, particularly during the first three months of pregnancy.
Clarithromycin is excreted principally by the liver and kidney, therefore caution must be exercised in its use in patients with impaired hepatic or renal function or in those concomitantly receiving potentially hepatotoxic drugs.
Attention should be paid to the possibility of cross resistance between clarithromycin and other macrolide drugs, as well as lincomycin and clindamycin.
Prolonged or repeated use of clarithromycin may result in overgrowth of non-susceptible bacteria. If super-infection occurs, clarithromycin should be discontinued and appropriate therapy instituted.
There have been post-marketing reports of colchicine toxicity with concomitant use of clarithromycin and colchicine, especially in the elderly, some of which occurred in patients with renal insufficiency. Deaths have been reported in some such patients (see section 4.5).
Pseudomembranous colitis has been reported with nearly all antibacterial agents, including macrolides, and may range in severity from mild to life-threatening. Clostridium difficile associated diarrhoea (CDAD) has been reported with use of nearly all antibacterial agents including clarithromycin, and may range in severity from mild diarrhoea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon, which may lead to overgrowth of C. difficile.
CDAD must be considered in all patients who present with diarrhoea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.
Exacerbation of symptoms of myasthenia gravis has been reported in patients receiving clarithromycin therapy.
4.5 Interaction with other medicinal products and other forms of interactions
The use of the following drugs is strictly contraindicated due to the potential for severe drug interaction effects:
Elevated cisapride levels have been reported in patients receiving clarithromycin and cisapride concomitantly. This may result in QT prolongation and cardiac arrhythmias including ventricular tachycardia, ventricular fibrillation and torsades de pointes. Similar effects have been observed in patients, taking clarithromycin and pimozide concomitantly (see section 4.3, Contraindications).
Macrolides have been reported to alter the metabolism of terfenadine resulting in increased levels of terfenadine which has occasionally been associated with cardiac arrhythmias, such as QT prolongation, ventricular tachycardia, ventricular fibrillation and torsades de pointes (see section 4.3, Contraindications). In one study in 14 healthy volunteers, the concomitant administration of clarithromycin and terfenadine resulted in a 2 to 3-fold increase in the serum level of the acid metabolite of terfenadine and in prolongation of the QT interval which did not lead to any clinically detectable effect. Similar effects have been observed with concomitant administration of astemizole and other macrolides.
Ergotamine/dihydroergotamine
Post-marketing reports indicate that co-administration of clarithromycin with ergotamine or dihydroergotamine has been associated with acute ergot toxicity characterized by vasospasm, and ischemia of the extremities and other tissues including the central nervous system. Concomitant administration of clarithromycin and these medicinal products is contraindicated (see section 4.3, Contraindications).
Effects of Other Medicinal Products on Clarithromycin
The following drugs are known or suspected to affect circulating concentrations of clarithromycin; clarithromycin dosage adjustment or consideration of alternative treatments may be required.
Efavirenz, nevirapine, rifampicin, rifabutin and rifapentine
Strong inducers of the cytochrome P450 metabolism system such as efavirenz, nevirapine, rifampicin, rifabutin, and rifapentine may accelerate the metabolism of clarithromycin and thus lower the plasma levels of clarithromycin, while increasing those of 14-(R)-hydroxy-clarithromycin (14-OH-clarithromycin), a metabolite that is also microbiologically active. Since the microbiological activities of clarithromycin and 14-OH-clarithromycin are different for different bacteria, the intended therapeutic effect could be impaired during concomitant administration of clarithromycin and enzyme inducers.
Fluconazole
Concomitant administration of fluconazole 200 mg daily and clarithromycin 500 mg twice daily to 21 healthy volunteers led to increases in the mean steady-state minimum clarithromycin concentration (Cmin) and area under the curve (AUC) of 33% and 18% respectively. Steady state concentrations of the active metabolite 14-OH-clarithromycin were not significantly affected by concomitant administration of fluconazole. No clarithromycin dose adjustment is necessary.
Ritonavir
A pharmacokinetic study demonstrated that the concomitant administration of ritonavir 200 mg every eight hours and clarithromycin 500 mg every 12 hours resulted in a marked inhibition of the metabolism of clarithromycin. The clarithromycin Cmax increased by 31%, Cmin increased 182% and AUC increased by 77% with concomitant administration of ritonavir. An essentially complete inhibition of the formation of 14-OH-clarithromycin was noted. Because of the large therapeutic window for clarithromycin, no dosage reduction should be necessary in patients with normal renal function. However, for patients with renal impairment, the following dosage adjustments should be considered: For patients with CLCR 30 to 60 mL/min the dose of clarithromycin should be reduced by 50%. For patients with CLCR <30 mL/min the dose of clarithromycin should be decreased by 75%. Doses of clarithromycin greater than 1 gm/day should not be coadministered with ritonavir.
Effect of Clarithromycin on Other Medicinal Products
Antiarrhythmics
There have been postmarketed reports of torsade de points occurring with the concurrent use of clarithromycin and quinidine or disopyramide. Electrocardiograms should be monitored for QTc prolongation during co-administration of clarithromycin with these drugs. Serum levels of these medications should be monitored during clarithromycin therapy.
CY3A4-based interactions
Co-administration of clarithromycin, known to inhibit CYP3A, and a drug primarily metabolized by CYP3A may be associated with elevations in drug concentrations that could increase or prolong both therapeutic and adverse effects of the concomitant drug. Clarithromycin should be used with caution in patients receiving treatment with other drugs known to be CYP3A enzyme substrates, especially if the CYP3A substrate has a narrow safety margin (e.g., carbamazepine) and/or the substrate is extensively metabolized by this enzyme. Dosage adjustments may be considered, and when possible, serum concentrations of drugs primarily metabolized by CYP3A should be monitored closely in patients concurrently receiving clarithromycin.
The following drugs or drug classes are known or suspected to be metabolized by the same CYP3A isozyme: alprazolam, astemizole, carbamazepine, cilostazol, cisapride, cyclosporine, disopyramide, ergot alkaloids, lovastatin, methylprednisolone, midazolam, omeprazole, oral anticoagulants (e.g. warfarin), pimozide, quinidine, rifabutin, sildenafil, simvastatin, tacrolimus, terfenadine, triazolam and vinblastine. Drugs interacting by similar mechanisms through other isozymes within the cytochrome P450 system include phenytoin, theophylline and valproate.
HMG-CoA Reductase Inhibitors
As with other macrolides, clarithromycin has been reported to increase concentrations of HMG-CoA reductase inhibitors (e.g., lovastatin and simvastatin). Rare reports of rhabdomyolysis have been reported in patients taking these drugs concomitantly.
Omeprazole
Clarithromycin (500 mg every 8 hours) was given in combination with omeprazole (40 mg daily) to healthy adult subjects. The steady-state plasma concentrations of omeprazole were increased (Cmax, AUC0-24, and t1/2 increased by 30%, 89%, and 34%, respectively), by the concomitant administration of clarithromycin. The mean 24-hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when omeprazole was co-administered with clarithromycin.
Oral anticoagulants
Spontaneous reports in the post-marketing period suggest that concomitant administration of clarithromycin and oral anticoagulants may potentiate the effects of the oral anticoagulants. Prothrombin times should be carefully monitored while patients are receiving clarithromycin and oral anticoagulants simultaneously.
Sildenafil, tadalafil and vardenafil
Each of these phosphodiesterase inhibitors is metabolized, at least in part, by CYP3A, and CYP3A may be inhibited by concomitantly administered clarithromycin. Co-administration of clarithromycin with sildenafil, tadalafil or vardenafil would likely result in increased phosphodiesterase inhibitor exposure. Reduction of sildenafil, tadalafil and vardenafil dosages should be considered when these drugs are co-administered with clarithromycin.
Theophylline, carbamazepine
Results of clinical studies indicate that there was a modest but statistically significant (p≤ 0.05) increase of circulating theophylline or carbamazepine levels when either of these drugs were administered concomitantly with clarithromycin.
Tolterodine
The primary route of metabolism for tolterodine is via the 2D6 isoform of cytochrome P450 (CYP2D6). However, in a subset of the population devoid of CYP2D6, the identified pathway of metabolism is via CYP3A. In this population subset, inhibition of CYP3A results in significantly higher serum concentrations of tolterodine. A reduction in tolterodine dosage may be necessary in the presence of CYP3A inhibitors, such as clarithromycin in the CYP2D6 poor metabolizer population.
Triazolobenzodiazepines (e.g., alprazolam, midazolam, triazolam)
When midazolam was co-administered with clarithromycin tablets (500 mg twice daily), midazolam AUC was increased 2.7-fold after intravenous administration of midazolam and 7-fold after oral administration. Concomitant administration of oral midazolam and clarithromycin should be avoided. If intravenous midazolam is co-administered with clarithromycin, the patient must be closely monitored to allow dose adjustment. The same precautions should also apply to other benzodiazepines that are metabolized by CYP3A, including triazolam and alprazolam. For benzodiazepines which are not dependent on CYP3A for their elimination (temazepam, nitrazepam, lorazepam), a clinically important interaction with clarithromycin is unlikely.
There have been post-marketing reports of drug interactions and central nervous system (CNS) effects (e.g., somnolence and confusion) with the concomitant use of clarithromycin and triazolam. Monitoring the patient for increased CNS pharmacological effects is suggested.
Other drug interactions
Colchicine
Colchicine is a substrate for both CYP3A and the efflux transporter, P-glycoprotein (Pgp). Clarithromycin and other macrolides are known to inhibit CYP3A and Pgp. When clarithromycin and colchicine are administered together, inhibition of Pgp and/or CYP3A by clarithromycin may lead to increased exposure to colchicine. Patients should be monitored for clinical symptoms of colchicine toxicity (see section 4.4 Warnings and Precautions).
Digoxin
Digoxin is thought to be a substrate for the efflux transporter, P-glycoprotein (Pgp). Clarithromycin is known to inhibit Pgp. When clarithromycin and digoxin are administered together, inhibition of Pgp by clarithromycin may lead to increased exposure to digoxin. Elevated digoxin serum concentrations in patients receiving clarithromycin and digoxin concomitantly have also been reported in post marketing surveillance. Some patients have shown clinical signs consistent with digoxin toxicity, including potentially fatal arrhythmias. Serum digoxin concentrations should be carefully monitored while patients are receiving digoxin and clarithromycin simultaneously.
Zidovudine
Simultaneous oral administration of clarithromycin tablets and zidovudine to HIV-infected adult patients may result in decreased steady-state zidovudine concentrations. Because clarithromycin appears to interfere with the absorption of simultaneously administered oral zidovudine, this interaction can be largely avoided by staggering the doses of clarithromycin and zidovudine. This interaction does not appear to occur in paediatric HIV-infected patients taking clarithromycin suspension with zidovudine or dideoxyinosine.
Bi-directional drug interactions
Atazanavir
Both clarithromycin and atazanavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction. Co-administration of clarithromycin (500 mg twice daily) with atazanavir (400 mg once daily) resulted in a 2-fold increase in exposure to clarithromycin and a 70% decrease in exposure to 14-OH-clarithromycin, with a 28% increase in the AUC of atazanavir. Because of the large therapeutic window for clarithromycin, no dosage reduction should be necessary in patients with normal renal function. For patients with moderate renal function (creatinine clearance 30 to 60 mL/min), the dose of clarithromycin should be decreased by 50%. For patients with creatinine clearance <30 mL/min, the dose of clarithromycin should be decreased by 75% using an appropriate clarithromycin formulation. Doses of clarithromycin greater than 1000 mg per day should not be co-administered with protease inhibitors.
Itraconazole
Both clarithromycin and itraconazole are substrates and inhibitors of CYP3A, leading to a bidirectional drug interaction. Clarithromycin may increase the plasma levels of itraconazole, while itraconazole may increase the plasma levels of clarithromycin. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged pharmacologic effect.
Saquinavir
Both clarithromycin and saquinavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction. Concomitant administration of clarithromycin (500 mg bid) and saquinavir (soft gelatin capsules, 1200 mg tid) to 12 healthy volunteers resulted in steady-state AUC and Cmax values of saquinavir which were 177% and 187% higher than those seen with saquinavir alone. Clarithromycin AUC and Cmax values were approximately 40% higher than those seen with clarithromycin alone. No dose adjustment is required when the two drugs are co-administered for a limited time at the doses/formulations studied. Observations from drug interaction studies using the soft gelatin capsule formulation may not be representative of the effects seen using the saquinavir hard gelatin capsule. Observations from drug interaction studies performed with saquinavir alone may not be representative of the effects seen with the combination therapy of saquinavir and ritonavir, therefore when this combination therapy is co-administered with clarithromycin consideration should be given to the potential effects of ritonavir on clarithromycin (see Section 4.5-Ritonavir).
Verapamil
Hypotension, bradyarrhythmias and lactic acidosis have been observed in patients taking clarithromycin and verapamil concomitantly.
4.8 Undesirable effects
Table 1 displays adverse events reported in patients taking clarithromycin in clinical studies. Adverse events are displayed by body system and frequency (common ≥ 1/100, < 1/10).
Table 1.
Adverse Events Reported in Clinical Studies
System Organ Class
Frequency
Adverse Events
Nervous system disorders
Common
headache
taste perversion
Gastrointestinal disorders
Common
diarrhoea
nausea
abdominal pain
dyspepsia
vomiting
Investigations
Common
hepatic enzyme increased
Post Marketing Experience
Clarithromycin is marketed in several different formulations. Table 2 is a compilation of adverse reactions for all formulations including clarithromycin immediate release tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Patient exposure is estimated to be greater than 1 billion patient treatment days for clarithromycin.
Table 2
Adverse Reactions from Post-Marketing Surveillance
System Organ Class
Adverse Reaction
Infections and infestations
oral candidiasis
Blood and lymphatic system disorders
leukopaenia
thrombocytopaenia
Immune System disorders
anaphylactic reaction hypersensitivity
Metabolism and nutrition disorders1
hypoglycaemia
Psychiatric disorders
psychotic disorder
hallucination
disorientation
confusional state
depersonalization
depression
anxiety
insomnia
abnormal dreams
Nervous system disorders
Convulsion
dizziness
ageusia
anosmia
dysgeusia
parosmia
Ear and labyrinth disorders
deafness
vertigo
tinnitus
Cardiac disorders2
torsade de pointes
electrocardiogram QT prolonged
ventricular tachycardia
Gastrointestinal disorders
pancreatitis acute
glossitis
stomatitis
tongue discoloration
tooth discoloration
Hepatobiliary disorders3
hepatic failure
hepatitis
hepatitis cholestatic
jaundice cholestatic
jaundice hepatocellular
hepatic function abnormal
Skin and subcutaneous tissue disorders
Stevens-Johnson syndrome
toxic epidermal necrolysis
urticaria
rash
Musculoskeletal and connective tissue disorders
myalgia
Renal and urinary disorders
nephritis interstitial
Investigations
blood creatinine increase
hepatic enzyme increased
1 There have been rare reports of hypoglycaemia, some of which have occurred in patients on concomitant oral hypoglycaemic agents or insulin.
2 As with other macrolides, QT prolongation, ventricular tachycardia, and torsades de pointes have rarely been reported with clarithromycin.
3 In very rare instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications.
There have been post-marketing reports of colchicine toxicity with concomitant use of clarithromycin and colchicine, especially in the elderly, some of which occurred in patients with renal insufficiency. Deaths have been reported in some such patients (see sections 4.4 Warnings and Precautions and 4.5 Interaction with other medicinal products and other forms of interactions).
Adverse events in immunocompromised patients: In AIDS and other immunocomprimised patients treated with the higher doses of clarithromycin over long periods of time for mycobacterial infections, it was often difficult to distinguish adverse events possibly associated with clarithromycin administration from underlying signs of HIV disease or intercurrent illness.
In adult patients, the most frequently reported adverse events by patients treated with total daily doses of 1000 mg and 2000mg of clarithromycin were: nausea, vomiting, taste perversion, abdominal pain, diarrhoea, rash, flatulence, headache, constipation, hearing disturbance, SGOT and SGTP elevations. Additional low-frequency events included dyspnoea, insomnia and dry mouth. The incidences were comparable for patients treated with 1000mg and 2000mg, but were generally about 3 to 4 times as frequent for those patients who received total daily doses of 4000mg of clarithromycin.
In these immunocompromised patients evaluations of laboratory values were made by analysing those values outside the seriously abnormal level (i.e. the extreme high or low limit) for the specified test. On the basis of these criteria, about 2% to 3% of those patients who received 1000mg or 2000mg of clarithromycin daily had seriously abnormal elevated levels of SGOT and SGPT, and abnormally low white blood cell and platelet counts. A lower percentage of patients in these two dosage groups also had elevated Blood Urea Nitrogen (BUN) levels. Slightly higher incidences of abnormal values were noted for patients who received 4000mg daily for all parameters except WBC.
4.9 Overdose
Reports indicate that the ingestion of large amounts of clarithromycin can be expected to produce gastrointestinal symptoms. Adverse reactions accompanying overdosage should be treated by gastric lavage and general supportive measures.
As with other macrolides, clarithromycin serum levels are not expected to be appreciably affected by haemodialysis or peritoneal dialysis.
One patient who had a history of bipolar disorder ingested 8 grams of clarithromycin and showed altered mental status, paranoid behaviour, hypokalaemia and hypoxaemia.
5.1 Pharmacodynamic properties
Clarithromycin is a semi-synthetic derivative of erythromycin A. It exerts its antibacterial action by binding to the 50s ribosomal sub-unit of susceptible bacteria and suppresses protein synthesis. It is highly potent against a wide variety of aerobic and anaerobic gram-positive and gram-negative organisms. The minimum inhibitory concentrations (MICs) of clarithromycin are generally two-fold lower than the MICs of erythromycin.
The 14-hydroxy metabolite of clarithromycin also has antimicrobial activity. The MICs of this metabolite are equal or two-fold higher than the MICs of the parent compound, except for H. influenzae where the 14-hydroxy metabolite is two-fold more active than the parent compound.
Klacid is usually active against the following organisms in vitro. Please see below for table of MIC breakpoints.
Gram-positive Bacteria: Staphylococcus aureus (methicillin susceptible); Streptococcus pyogenes (Group A beta-hemolytic streptococci); alpha-hemolytic streptococci (viridans group); Streptococcus (Diplococcus) pneumoniae; Streptococcus agalactiae; Listeria monocytogenes.
Gram-negative Bacteria: Haemophilus influenzae; Haemophilus parainfluenzae; Moraxella (Branhamella) catarrhalis; Neisseria gonorrhoeae; Legionella pneumophila; Bordetella pertussis; Helicobacter pylori; Campylobacter jejuni.
Mycoplasma: Mycoplasma pneumoniae; Ureaplasma urealyticum.
Other Organisms: Chlamydia trachomatis; Mycobacterium avium; Mycobacterium leprae.
Anaerobes: Macrolide-susceptible Bacteroides fragilis; Clostridium perfringens; Peptococcus species; Peptostreptococcus species; Propionibacterium acnes.
Clarithromycin has bactericidal activity against several bacterial strains. The organisms include Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Moraxella (Branhamella) catarrhalis, Neisseria gonorrhoeae, H. pylori and Campylobacter spp.
H. pylori is associated with acid peptic disease including duodenal ulcer and gastric ulcer in which about 95% and 80% of patients respectively are infected with the agent. H. pylori is also implicated as a major contribution factor in the development of gastric and ulcer recurrence in such patients.
Clarithromycin has been used in small numbers of patients in other treatment regimens. Possible kinetic interactions have not been fully investigated. These regimens include:
Clarithromycin plus tinidazole and omeprazole; clarithromycin plus tetracycline, bismuth subsalicylate and ranitidine; clarithromycin plus ranitidine alone.
Clinical studies using various different H. pylori eradication regimens have shown that eradication of H. pylori prevents ulcer recurrence.
The following breakpoints for clarithromycin, separating susceptible organisms from resistant organisms, have been established by the European Committee for Antimicrobial Susceptibility Testing (EUCAST).
Breakpoints (MIC, μg/ml)
Microorganism
Susceptible (£)
Resistant (>)
Streptococcus spp.
0.25 mg/ml
0.5 mg/ml
Staphylococcus spp.
1 mg/ml
2 mg/ml
Haemophilus spp.
1 mg/ml
32 mg/ml
Moraxella catarrhalis
0.25 mg/ml
0.5 mg/ml
Clarithromycin is used for the eradication of H. pylori; minimum inhibitory concentration (MIC) ≤ 0.25 mg/ml which has been established as the susceptible breakpoint by the Clinical and Laboratory Standards Institute (CLSI).
Efavirenz, nevirapine, rifampicin, rifabutin and rifapentine
Strong inducers of the cytochrome P450 metabolism system such as efavirenz, nevirapine, rifampicin, rifabutin, and rifapentine may accelerate the metabolism of clarithromycin and thus lower the plasma levels of clarithromycin, while increasing those of 14-(R)-hydroxy-clarithromycin (14-OH-clarithromycin), a metabolite that is also microbiologically active. Since the microbiological activities of clarithromycin and 14-OH-clarithromycin are different for different bacteria, the intended therapeutic effect could be impaired during concomitant administration of clarithromycin and enzyme inducers.
Fluconazole
Concomitant administration of fluconazole 200 mg daily and clarithromycin 500 mg twice daily to 21 healthy volunteers led to increases in the mean steady-state minimum clarithromycin concentration (Cmin) and area under the curve (AUC) of 33% and 18% respectively. Steady state concentrations of the active metabolite 14-OH-clarithromycin were not significantly affected by concomitant administration of fluconazole. No clarithromycin dose adjustment is necessary.
Ritonavir
A pharmacokinetic study demonstrated that the concomitant administration of ritonavir 200 mg every eight hours and clarithromycin 500 mg every 12 hours resulted in a marked inhibition of the metabolism of clarithromycin. The clarithromycin Cmax increased by 31%, Cmin increased 182% and AUC increased by 77% with concomitant administration of ritonavir. An essentially complete inhibition of the formation of 14-OH-clarithromycin was noted. Because of the large therapeutic window for clarithromycin, no dosage reduction should be necessary in patients with normal renal function. However, for patients with renal impairment, the following dosage adjustments should be considered: For patients with CLCR 30 to 60 mL/min the dose of clarithromycin should be reduced by 50%. For patients with CLCR <30 mL/min the dose of clarithromycin should be decreased by 75%. Doses of clarithromycin greater than 1 gm/day should not be coadministered with ritonavir.
Effect of Clarithromycin on Other Medicinal Products
Antiarrhythmics
There have been postmarketed reports of torsade de points occurring with the concurrent use of clarithromycin and quinidine or disopyramide. Electrocardiograms should be monitored for QTc prolongation during co-administration of clarithromycin with these drugs. Serum levels of these medications should be monitored during clarithromycin therapy.
CY3A4-based interactions
Co-administration of clarithromycin, known to inhibit CYP3A, and a drug primarily metabolized by CYP3A may be associated with elevations in drug concentrations that could increase or prolong both therapeutic and adverse effects of the concomitant drug. Clarithromycin should be used with caution in patients receiving treatment with other drugs known to be CYP3A enzyme substrates, especially if the CYP3A substrate has a narrow safety margin (e.g., carbamazepine) and/or the substrate is extensively metabolized by this enzyme. Dosage adjustments may be considered, and when possible, serum concentrations of drugs primarily metabolized by CYP3A should be monitored closely in patients concurrently receiving clarithromycin.
The following drugs or drug classes are known or suspected to be metabolized by the same CYP3A isozyme: alprazolam, astemizole, carbamazepine, cilostazol, cisapride, cyclosporine, disopyramide, ergot alkaloids, lovastatin, methylprednisolone, midazolam, omeprazole, oral anticoagulants (e.g. warfarin), pimozide, quinidine, rifabutin, sildenafil, simvastatin, tacrolimus, terfenadine, triazolam and vinblastine. Drugs interacting by similar mechanisms through other isozymes within the cytochrome P450 system include phenytoin, theophylline and valproate.
HMG-CoA Reductase Inhibitors
As with other macrolides, clarithromycin has been reported to increase concentrations of HMG-CoA reductase inhibitors (e.g., lovastatin and simvastatin). Rare reports of rhabdomyolysis have been reported in patients taking these drugs concomitantly.
Omeprazole
Clarithromycin (500 mg every 8 hours) was given in combination with omeprazole (40 mg daily) to healthy adult subjects. The steady-state plasma concentrations of omeprazole were increased (Cmax, AUC0-24, and t1/2 increased by 30%, 89%, and 34%, respectively), by the concomitant administration of clarithromycin. The mean 24-hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when omeprazole was co-administered with clarithromycin.
Oral anticoagulants
Spontaneous reports in the post-marketing period suggest that concomitant administration of clarithromycin and oral anticoagulants may potentiate the effects of the oral anticoagulants. Prothrombin times should be carefully monitored while patients are receiving clarithromycin and oral anticoagulants simultaneously.
Sildenafil, tadalafil and vardenafil
Each of these phosphodiesterase inhibitors is metabolized, at least in part, by CYP3A, and CYP3A may be inhibited by concomitantly administered clarithromycin. Co-administration of clarithromycin with sildenafil, tadalafil or vardenafil would likely result in increased phosphodiesterase inhibitor exposure. Reduction of sildenafil, tadalafil and vardenafil dosages should be considered when these drugs are co-administered with clarithromycin.
Theophylline, carbamazepine
Results of clinical studies indicate that there was a modest but statistically significant (p≤ 0.05) increase of circulating theophylline or carbamazepine levels when either of these drugs were administered concomitantly with clarithromycin.
Tolterodine
The primary route of metabolism for tolterodine is via the 2D6 isoform of cytochrome P450 (CYP2D6). However, in a subset of the population devoid of CYP2D6, the identified pathway of metabolism is via CYP3A. In this population subset, inhibition of CYP3A results in significantly higher serum concentrations of tolterodine. A reduction in tolterodine dosage may be necessary in the presence of CYP3A inhibitors, such as clarithromycin in the CYP2D6 poor metabolizer population.
Triazolobenzodiazepines (e.g., alprazolam, midazolam, triazolam)
When midazolam was co-administered with clarithromycin tablets (500 mg twice daily), midazolam AUC was increased 2.7-fold after intravenous administration of midazolam and 7-fold after oral administration. Concomitant administration of oral midazolam and clarithromycin should be avoided. If intravenous midazolam is co-administered with clarithromycin, the patient must be closely monitored to allow dose adjustment. The same precautions should also apply to other benzodiazepines that are metabolized by CYP3A, including triazolam and alprazolam. For benzodiazepines which are not dependent on CYP3A for their elimination (temazepam, nitrazepam, lorazepam), a clinically important interaction with clarithromycin is unlikely.
There have been post-marketing reports of drug interactions and central nervous system (CNS) effects (e.g., somnolence and confusion) with the concomitant use of clarithromycin and triazolam. Monitoring the patient for increased CNS pharmacological effects is suggested.
Other drug interactions
Colchicine
Colchicine is a substrate for both CYP3A and the efflux transporter, P-glycoprotein (Pgp). Clarithromycin and other macrolides are known to inhibit CYP3A and Pgp. When clarithromycin and colchicine are administered together, inhibition of Pgp and/or CYP3A by clarithromycin may lead to increased exposure to colchicine. Patients should be monitored for clinical symptoms of colchicine toxicity (see section 4.4 Warnings and Precautions).
Digoxin
Digoxin is thought to be a substrate for the efflux transporter, P-glycoprotein (Pgp). Clarithromycin is known to inhibit Pgp. When clarithromycin and digoxin are administered together, inhibition of Pgp by clarithromycin may lead to increased exposure to digoxin. Elevated digoxin serum concentrations in patients receiving clarithromycin and digoxin concomitantly have also been reported in post marketing surveillance. Some patients have shown clinical signs consistent with digoxin toxicity, including potentially fatal arrhythmias. Serum digoxin concentrations should be carefully monitored while patients are receiving digoxin and clarithromycin simultaneously.
Zidovudine
Simultaneous oral administration of clarithromycin tablets and zidovudine to HIV-infected adult patients may result in decreased steady-state zidovudine concentrations. Because clarithromycin appears to interfere with the absorption of simultaneously administered oral zidovudine, this interaction can be largely avoided by staggering the doses of clarithromycin and zidovudine. This interaction does not appear to occur in paediatric HIV-infected patients taking clarithromycin suspension with zidovudine or dideoxyinosine.
Bi-directional drug interactions
Atazanavir
Both clarithromycin and atazanavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction. Co-administration of clarithromycin (500 mg twice daily) with atazanavir (400 mg once daily) resulted in a 2-fold increase in exposure to clarithromycin and a 70% decrease in exposure to 14-OH-clarithromycin, with a 28% increase in the AUC of atazanavir. Because of the large therapeutic window for clarithromycin, no dosage reduction should be necessary in patients with normal renal function. For patients with moderate renal function (creatinine clearance 30 to 60 mL/min), the dose of clarithromycin should be decreased by 50%. For patients with creatinine clearance <30 mL/min, the dose of clarithromycin should be decreased by 75% using an appropriate clarithromycin formulation. Doses of clarithromycin greater than 1000 mg per day should not be co-administered with protease inhibitors.
Itraconazole
Both clarithromycin and itraconazole are substrates and inhibitors of CYP3A, leading to a bidirectional drug interaction. Clarithromycin may increase the plasma levels of itraconazole, while itraconazole may increase the plasma levels of clarithromycin. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged pharmacologic effect.
Saquinavir
Both clarithromycin and saquinavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction. Concomitant administration of clarithromycin (500 mg bid) and saquinavir (soft gelatin capsules, 1200 mg tid) to 12 healthy volunteers resulted in steady-state AUC and Cmax values of saquinavir which were 177% and 187% higher than those seen with saquinavir alone. Clarithromycin AUC and Cmax values were approximately 40% higher than those seen with clarithromycin alone. No dose adjustment is required when the two drugs are co-administered for a limited time at the doses/formulations studied. Observations from drug interaction studies using the soft gelatin capsule formulation may not be representative of the effects seen using the saquinavir hard gelatin capsule. Observations from drug interaction studies performed with saquinavir alone may not be representative of the effects seen with the combination therapy of saquinavir and ritonavir, therefore when this combination therapy is co-administered with clarithromycin consideration should be given to the potential effects of ritonavir on clarithromycin (see Section 4.5-Ritonavir).
Verapamil
Hypotension, bradyarrhythmias and lactic acidosis have been observed in patients taking clarithromycin and verapamil concomitantly.
4.8 Undesirable effects
Table 1 displays adverse events reported in patients taking clarithromycin in clinical studies. Adverse events are displayed by body system and frequency (common ≥ 1/100, < 1/10).
Table 1.
Adverse Events Reported in Clinical Studies
System Organ Class
Frequency
Adverse Events
Nervous system disorders
Common
headache
taste perversion
Gastrointestinal disorders
Common
diarrhoea
nausea
abdominal pain
dyspepsia
vomiting
Investigations
Common
hepatic enzyme increased
Post Marketing Experience
Clarithromycin is marketed in several different formulations. Table 2 is a compilation of adverse reactions for all formulations including clarithromycin immediate release tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Patient exposure is estimated to be greater than 1 billion patient treatment days for clarithromycin.
Table 2
Adverse Reactions from Post-Marketing Surveillance
System Organ Class
Adverse Reaction
Infections and infestations
oral candidiasis
Blood and lymphatic system disorders
leukopaenia
thrombocytopaenia
Immune System disorders
anaphylactic reaction hypersensitivity
Metabolism and nutrition disorders1
hypoglycaemia
Psychiatric disorders
psychotic disorder
hallucination
disorientation
confusional state
depersonalization
depression
anxiety
insomnia
abnormal dreams
Nervous system disorders
Convulsion
dizziness
ageusia
anosmia
dysgeusia
parosmia
Ear and labyrinth disorders
deafness
vertigo
tinnitus
Cardiac disorders2
torsade de pointes
electrocardiogram QT prolonged
ventricular tachycardia
Gastrointestinal disorders
pancreatitis acute
glossitis
stomatitis
tongue discoloration
tooth discoloration
Hepatobiliary disorders3
hepatic failure
hepatitis
hepatitis cholestatic
jaundice cholestatic
jaundice hepatocellular
hepatic function abnormal
Skin and subcutaneous tissue disorders
Stevens-Johnson syndrome
toxic epidermal necrolysis
urticaria
rash
Musculoskeletal and connective tissue disorders
myalgia
Renal and urinary disorders
nephritis interstitial
Investigations
blood creatinine increase
hepatic enzyme increased
1 There have been rare reports of hypoglycaemia, some of which have occurred in patients on concomitant oral hypoglycaemic agents or insulin.
2 As with other macrolides, QT prolongation, ventricular tachycardia, and torsades de pointes have rarely been reported with clarithromycin.
3 In very rare instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications.
There have been post-marketing reports of colchicine toxicity with concomitant use of clarithromycin and colchicine, especially in the elderly, some of which occurred in patients with renal insufficiency. Deaths have been reported in some such patients (see sections 4.4 Warnings and Precautions and 4.5 Interaction with other medicinal products and other forms of interactions).
Adverse events in immunocompromised patients: In AIDS and other immunocomprimised patients treated with the higher doses of clarithromycin over long periods of time for mycobacterial infections, it was often difficult to distinguish adverse events possibly associated with clarithromycin administration from underlying signs of HIV disease or intercurrent illness.
In adult patients, the most frequently reported adverse events by patients treated with total daily doses of 1000 mg and 2000mg of clarithromycin were: nausea, vomiting, taste perversion, abdominal pain, diarrhoea, rash, flatulence, headache, constipation, hearing disturbance, SGOT and SGTP elevations. Additional low-frequency events included dyspnoea, insomnia and dry mouth. The incidences were comparable for patients treated with 1000mg and 2000mg, but were generally about 3 to 4 times as frequent for those patients who received total daily doses of 4000mg of clarithromycin.
In these immunocompromised patients evaluations of laboratory values were made by analysing those values outside the seriously abnormal level (i.e. the extreme high or low limit) for the specified test. On the basis of these criteria, about 2% to 3% of those patients who received 1000mg or 2000mg of clarithromycin daily had seriously abnormal elevated levels of SGOT and SGPT, and abnormally low white blood cell and platelet counts. A lower percentage of patients in these two dosage groups also had elevated Blood Urea Nitrogen (BUN) levels. Slightly higher incidences of abnormal values were noted for patients who received 4000mg daily for all parameters except WBC.
4.9 Overdose
Reports indicate that the ingestion of large amounts of clarithromycin can be expected to produce gastrointestinal symptoms. Adverse reactions accompanying overdosage should be treated by gastric lavage and general supportive measures.
As with other macrolides, clarithromycin serum levels are not expected to be appreciably affected by haemodialysis or peritoneal dialysis.
One patient who had a history of bipolar disorder ingested 8 grams of clarithromycin and showed altered mental status, paranoid behaviour, hypokalaemia and hypoxaemia.
5.1 Pharmacodynamic properties
Clarithromycin is a semi-synthetic derivative of erythromycin A. It exerts its antibacterial action by binding to the 50s ribosomal sub-unit of susceptible bacteria and suppresses protein synthesis. It is highly potent against a wide variety of aerobic and anaerobic gram-positive and gram-negative organisms. The minimum inhibitory concentrations (MICs) of clarithromycin are generally two-fold lower than the MICs of erythromycin.
The 14-hydroxy metabolite of clarithromycin also has antimicrobial activity. The MICs of this metabolite are equal or two-fold higher than the MICs of the parent compound, except for H. influenzae where the 14-hydroxy metabolite is two-fold more active than the parent compound.
Klacid is usually active against the following organisms in vitro. Please see below for table of MIC breakpoints.
Gram-positive Bacteria: Staphylococcus aureus (methicillin susceptible); Streptococcus pyogenes (Group A beta-hemolytic streptococci); alpha-hemolytic streptococci (viridans group); Streptococcus (Diplococcus) pneumoniae; Streptococcus agalactiae; Listeria monocytogenes.
Gram-negative Bacteria: Haemophilus influenzae; Haemophilus parainfluenzae; Moraxella (Branhamella) catarrhalis; Neisseria gonorrhoeae; Legionella pneumophila; Bordetella pertussis; Helicobacter pylori; Campylobacter jejuni.
Mycoplasma: Mycoplasma pneumoniae; Ureaplasma urealyticum.
Other Organisms: Chlamydia trachomatis; Mycobacterium avium; Mycobacterium leprae.
Anaerobes: Macrolide-susceptible Bacteroides fragilis; Clostridium perfringens; Peptococcus species; Peptostreptococcus species; Propionibacterium acnes.
Clarithromycin has bactericidal activity against several bacterial strains. The organisms include Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Moraxella (Branhamella) catarrhalis, Neisseria gonorrhoeae, H. pylori and Campylobacter spp.
H. pylori is associated with acid peptic disease including duodenal ulcer and gastric ulcer in which about 95% and 80% of patients respectively are infected with the agent. H. pylori is also implicated as a major contribution factor in the development of gastric and ulcer recurrence in such patients.
Clarithromycin has been used in small numbers of patients in other treatment regimens. Possible kinetic interactions have not been fully investigated. These regimens include:
Clarithromycin plus tinidazole and omeprazole; clarithromycin plus tetracycline, bismuth subsalicylate and ranitidine; clarithromycin plus ranitidine alone.
Clinical studies using various different H. pylori eradication regimens have shown that eradication of H. pylori prevents ulcer recurrence.
The following breakpoints for clarithromycin, separating susceptible organisms from resistant organisms, have been established by the European Committee for Antimicrobial Susceptibility Testing (EUCAST).
Breakpoints (MIC, μg/ml)
Microorganism
Susceptible (£)
Resistant (>)
Streptococcus spp.
0.25 mg/ml
0.5 mg/ml
Staphylococcus spp.
1 mg/ml
2 mg/ml
Haemophilus spp.
1 mg/ml
32 mg/ml
Moraxella catarrhalis
0.25 mg/ml
0.5 mg/ml
Clarithromycin is used for the eradication of H. pylori; minimum inhibitory concentration (MIC) ≤ 0.25 mg/ml which has been established as the susceptible breakpoint by the Clinical and Laboratory Standards Institute (CLSI).
Fluconazole
Concomitant administration of fluconazole 200 mg daily and clarithromycin 500 mg twice daily to 21 healthy volunteers led to increases in the mean steady-state minimum clarithromycin concentration (Cmin) and area under the curve (AUC) of 33% and 18% respectively. Steady state concentrations of the active metabolite 14-OH-clarithromycin were not significantly affected by concomitant administration of fluconazole. No clarithromycin dose adjustment is necessary.
Ritonavir
A pharmacokinetic study demonstrated that the concomitant administration of ritonavir 200 mg every eight hours and clarithromycin 500 mg every 12 hours resulted in a marked inhibition of the metabolism of clarithromycin. The clarithromycin Cmax increased by 31%, Cmin increased 182% and AUC increased by 77% with concomitant administration of ritonavir. An essentially complete inhibition of the formation of 14-OH-clarithromycin was noted. Because of the large therapeutic window for clarithromycin, no dosage reduction should be necessary in patients with normal renal function. However, for patients with renal impairment, the following dosage adjustments should be considered: For patients with CLCR 30 to 60 mL/min the dose of clarithromycin should be reduced by 50%. For patients with CLCR <30 mL/min the dose of clarithromycin should be decreased by 75%. Doses of clarithromycin greater than 1 gm/day should not be coadministered with ritonavir.
Effect of Clarithromycin on Other Medicinal Products
Antiarrhythmics
There have been postmarketed reports of torsade de points occurring with the concurrent use of clarithromycin and quinidine or disopyramide. Electrocardiograms should be monitored for QTc prolongation during co-administration of clarithromycin with these drugs. Serum levels of these medications should be monitored during clarithromycin therapy.
CY3A4-based interactions
Co-administration of clarithromycin, known to inhibit CYP3A, and a drug primarily metabolized by CYP3A may be associated with elevations in drug concentrations that could increase or prolong both therapeutic and adverse effects of the concomitant drug. Clarithromycin should be used with caution in patients receiving treatment with other drugs known to be CYP3A enzyme substrates, especially if the CYP3A substrate has a narrow safety margin (e.g., carbamazepine) and/or the substrate is extensively metabolized by this enzyme. Dosage adjustments may be considered, and when possible, serum concentrations of drugs primarily metabolized by CYP3A should be monitored closely in patients concurrently receiving clarithromycin.
The following drugs or drug classes are known or suspected to be metabolized by the same CYP3A isozyme: alprazolam, astemizole, carbamazepine, cilostazol, cisapride, cyclosporine, disopyramide, ergot alkaloids, lovastatin, methylprednisolone, midazolam, omeprazole, oral anticoagulants (e.g. warfarin), pimozide, quinidine, rifabutin, sildenafil, simvastatin, tacrolimus, terfenadine, triazolam and vinblastine. Drugs interacting by similar mechanisms through other isozymes within the cytochrome P450 system include phenytoin, theophylline and valproate.
HMG-CoA Reductase Inhibitors
As with other macrolides, clarithromycin has been reported to increase concentrations of HMG-CoA reductase inhibitors (e.g., lovastatin and simvastatin). Rare reports of rhabdomyolysis have been reported in patients taking these drugs concomitantly.
Omeprazole
Clarithromycin (500 mg every 8 hours) was given in combination with omeprazole (40 mg daily) to healthy adult subjects. The steady-state plasma concentrations of omeprazole were increased (Cmax, AUC0-24, and t1/2 increased by 30%, 89%, and 34%, respectively), by the concomitant administration of clarithromycin. The mean 24-hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when omeprazole was co-administered with clarithromycin.
Oral anticoagulants
Spontaneous reports in the post-marketing period suggest that concomitant administration of clarithromycin and oral anticoagulants may potentiate the effects of the oral anticoagulants. Prothrombin times should be carefully monitored while patients are receiving clarithromycin and oral anticoagulants simultaneously.
Sildenafil, tadalafil and vardenafil
Each of these phosphodiesterase inhibitors is metabolized, at least in part, by CYP3A, and CYP3A may be inhibited by concomitantly administered clarithromycin. Co-administration of clarithromycin with sildenafil, tadalafil or vardenafil would likely result in increased phosphodiesterase inhibitor exposure. Reduction of sildenafil, tadalafil and vardenafil dosages should be considered when these drugs are co-administered with clarithromycin.
Theophylline, carbamazepine
Results of clinical studies indicate that there was a modest but statistically significant (p≤ 0.05) increase of circulating theophylline or carbamazepine levels when either of these drugs were administered concomitantly with clarithromycin.
Tolterodine
The primary route of metabolism for tolterodine is via the 2D6 isoform of cytochrome P450 (CYP2D6). However, in a subset of the population devoid of CYP2D6, the identified pathway of metabolism is via CYP3A. In this population subset, inhibition of CYP3A results in significantly higher serum concentrations of tolterodine. A reduction in tolterodine dosage may be necessary in the presence of CYP3A inhibitors, such as clarithromycin in the CYP2D6 poor metabolizer population.
Triazolobenzodiazepines (e.g., alprazolam, midazolam, triazolam)
When midazolam was co-administered with clarithromycin tablets (500 mg twice daily), midazolam AUC was increased 2.7-fold after intravenous administration of midazolam and 7-fold after oral administration. Concomitant administration of oral midazolam and clarithromycin should be avoided. If intravenous midazolam is co-administered with clarithromycin, the patient must be closely monitored to allow dose adjustment. The same precautions should also apply to other benzodiazepines that are metabolized by CYP3A, including triazolam and alprazolam. For benzodiazepines which are not dependent on CYP3A for their elimination (temazepam, nitrazepam, lorazepam), a clinically important interaction with clarithromycin is unlikely.
There have been post-marketing reports of drug interactions and central nervous system (CNS) effects (e.g., somnolence and confusion) with the concomitant use of clarithromycin and triazolam. Monitoring the patient for increased CNS pharmacological effects is suggested.
Other drug interactions
Colchicine
Colchicine is a substrate for both CYP3A and the efflux transporter, P-glycoprotein (Pgp). Clarithromycin and other macrolides are known to inhibit CYP3A and Pgp. When clarithromycin and colchicine are administered together, inhibition of Pgp and/or CYP3A by clarithromycin may lead to increased exposure to colchicine. Patients should be monitored for clinical symptoms of colchicine toxicity (see section 4.4 Warnings and Precautions).
Digoxin
Digoxin is thought to be a substrate for the efflux transporter, P-glycoprotein (Pgp). Clarithromycin is known to inhibit Pgp. When clarithromycin and digoxin are administered together, inhibition of Pgp by clarithromycin may lead to increased exposure to digoxin. Elevated digoxin serum concentrations in patients receiving clarithromycin and digoxin concomitantly have also been reported in post marketing surveillance. Some patients have shown clinical signs consistent with digoxin toxicity, including potentially fatal arrhythmias. Serum digoxin concentrations should be carefully monitored while patients are receiving digoxin and clarithromycin simultaneously.
Zidovudine
Simultaneous oral administration of clarithromycin tablets and zidovudine to HIV-infected adult patients may result in decreased steady-state zidovudine concentrations. Because clarithromycin appears to interfere with the absorption of simultaneously administered oral zidovudine, this interaction can be largely avoided by staggering the doses of clarithromycin and zidovudine. This interaction does not appear to occur in paediatric HIV-infected patients taking clarithromycin suspension with zidovudine or dideoxyinosine.
Bi-directional drug interactions
Atazanavir
Both clarithromycin and atazanavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction. Co-administration of clarithromycin (500 mg twice daily) with atazanavir (400 mg once daily) resulted in a 2-fold increase in exposure to clarithromycin and a 70% decrease in exposure to 14-OH-clarithromycin, with a 28% increase in the AUC of atazanavir. Because of the large therapeutic window for clarithromycin, no dosage reduction should be necessary in patients with normal renal function. For patients with moderate renal function (creatinine clearance 30 to 60 mL/min), the dose of clarithromycin should be decreased by 50%. For patients with creatinine clearance <30 mL/min, the dose of clarithromycin should be decreased by 75% using an appropriate clarithromycin formulation. Doses of clarithromycin greater than 1000 mg per day should not be co-administered with protease inhibitors.
Itraconazole
Both clarithromycin and itraconazole are substrates and inhibitors of CYP3A, leading to a bidirectional drug interaction. Clarithromycin may increase the plasma levels of itraconazole, while itraconazole may increase the plasma levels of clarithromycin. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged pharmacologic effect.
Saquinavir
Both clarithromycin and saquinavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction. Concomitant administration of clarithromycin (500 mg bid) and saquinavir (soft gelatin capsules, 1200 mg tid) to 12 healthy volunteers resulted in steady-state AUC and Cmax values of saquinavir which were 177% and 187% higher than those seen with saquinavir alone. Clarithromycin AUC and Cmax values were approximately 40% higher than those seen with clarithromycin alone. No dose adjustment is required when the two drugs are co-administered for a limited time at the doses/formulations studied. Observations from drug interaction studies using the soft gelatin capsule formulation may not be representative of the effects seen using the saquinavir hard gelatin capsule. Observations from drug interaction studies performed with saquinavir alone may not be representative of the effects seen with the combination therapy of saquinavir and ritonavir, therefore when this combination therapy is co-administered with clarithromycin consideration should be given to the potential effects of ritonavir on clarithromycin (see Section 4.5-Ritonavir).
Verapamil
Hypotension, bradyarrhythmias and lactic acidosis have been observed in patients taking clarithromycin and verapamil concomitantly.
4.8 Undesirable effects
Table 1 displays adverse events reported in patients taking clarithromycin in clinical studies. Adverse events are displayed by body system and frequency (common ≥ 1/100, < 1/10).
Table 1.
Adverse Events Reported in Clinical Studies
System Organ Class |
Frequency |
Adverse Events |
Nervous system disorders
|
Common |
headache taste perversion |
Gastrointestinal disorders |
Common |
diarrhoea nausea abdominal pain dyspepsia vomiting |
Investigations |
Common |
hepatic enzyme increased |
Post Marketing Experience
Clarithromycin is marketed in several different formulations. Table 2 is a compilation of adverse reactions for all formulations including clarithromycin immediate release tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Patient exposure is estimated to be greater than 1 billion patient treatment days for clarithromycin.
Table 2
Adverse Reactions from Post-Marketing Surveillance
System Organ Class |
Adverse Reaction |
Infections and infestations |
oral candidiasis |
Blood and lymphatic system disorders |
leukopaenia thrombocytopaenia |
Immune System disorders |
anaphylactic reaction hypersensitivity |
Metabolism and nutrition disorders1 |
hypoglycaemia |
Psychiatric disorders |
psychotic disorder hallucination |
|
disorientation |
|
confusional state |
|
depersonalization depression anxiety insomnia abnormal dreams |
Nervous system disorders |
Convulsion dizziness ageusia anosmia dysgeusia parosmia |
Ear and labyrinth disorders |
deafness vertigo tinnitus |
Cardiac disorders2 |
torsade de pointes electrocardiogram QT prolonged ventricular tachycardia |
Gastrointestinal disorders |
pancreatitis acute glossitis stomatitis tongue discoloration tooth discoloration |
Hepatobiliary disorders3 |
hepatic failure hepatitis hepatitis cholestatic jaundice cholestatic jaundice hepatocellular hepatic function abnormal |
Skin and subcutaneous tissue disorders |
Stevens-Johnson syndrome toxic epidermal necrolysis urticaria rash |
Musculoskeletal and connective tissue disorders |
myalgia |
Renal and urinary disorders |
nephritis interstitial |
Investigations |
blood creatinine increase hepatic enzyme increased |
1 There have been rare reports of hypoglycaemia, some of which have occurred in patients on concomitant oral hypoglycaemic agents or insulin. 2 As with other macrolides, QT prolongation, ventricular tachycardia, and torsades de pointes have rarely been reported with clarithromycin. 3 In very rare instances, hepatic failure with fatal outcome has been reported and generally has been associated with serious underlying diseases and/or concomitant medications. |
There have been post-marketing reports of colchicine toxicity with concomitant use of clarithromycin and colchicine, especially in the elderly, some of which occurred in patients with renal insufficiency. Deaths have been reported in some such patients (see sections 4.4 Warnings and Precautions and 4.5 Interaction with other medicinal products and other forms of interactions).
Adverse events in immunocompromised patients: In AIDS and other immunocomprimised patients treated with the higher doses of clarithromycin over long periods of time for mycobacterial infections, it was often difficult to distinguish adverse events possibly associated with clarithromycin administration from underlying signs of HIV disease or intercurrent illness.
In adult patients, the most frequently reported adverse events by patients treated with total daily doses of 1000 mg and 2000mg of clarithromycin were: nausea, vomiting, taste perversion, abdominal pain, diarrhoea, rash, flatulence, headache, constipation, hearing disturbance, SGOT and SGTP elevations. Additional low-frequency events included dyspnoea, insomnia and dry mouth. The incidences were comparable for patients treated with 1000mg and 2000mg, but were generally about 3 to 4 times as frequent for those patients who received total daily doses of 4000mg of clarithromycin.
In these immunocompromised patients evaluations of laboratory values were made by analysing those values outside the seriously abnormal level (i.e. the extreme high or low limit) for the specified test. On the basis of these criteria, about 2% to 3% of those patients who received 1000mg or 2000mg of clarithromycin daily had seriously abnormal elevated levels of SGOT and SGPT, and abnormally low white blood cell and platelet counts. A lower percentage of patients in these two dosage groups also had elevated Blood Urea Nitrogen (BUN) levels. Slightly higher incidences of abnormal values were noted for patients who received 4000mg daily for all parameters except WBC.
4.9 Overdose
Reports indicate that the ingestion of large amounts of clarithromycin can be expected to produce gastrointestinal symptoms. Adverse reactions accompanying overdosage should be treated by gastric lavage and general supportive measures.
As with other macrolides, clarithromycin serum levels are not expected to be appreciably affected by haemodialysis or peritoneal dialysis.
One patient who had a history of bipolar disorder ingested 8 grams of clarithromycin and showed altered mental status, paranoid behaviour, hypokalaemia and hypoxaemia.
Breakpoints (MIC, μg/ml)
Microorganism
Susceptible (£)
Resistant (>)
Streptococcus spp.
0.25 mg/ml
0.5 mg/ml
Staphylococcus spp.
1 mg/ml
2 mg/ml
Haemophilus spp.
1 mg/ml
32 mg/ml
Moraxella catarrhalis
0.25 mg/ml
0.5 mg/ml
Clarithromycin is used for the eradication of H. pylori; minimum inhibitory concentration (MIC) ≤ 0.25 mg/ml which has been established as the susceptible breakpoint by the Clinical and Laboratory Standards Institute (CLSI).
Updated on 05 October 2009
Reasons for updating
- Change to side-effects
- Change to drug interactions
Updated on 30 December 2008
Reasons for updating
- Change to date of revision
Updated on 28 October 2008
Reasons for updating
- Change of manufacturer
Updated on 14 May 2006
Reasons for updating
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 05 May 2006
Reasons for updating
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 21 April 2006
Reasons for updating
- Change to section 4.4 - Special warnings and precautions for use
- Change to section 4.5 - Interaction with other medicinal products and other forms of interaction
- Change to section 4.8 - Undesirable effects
- Change to section 10 - Date of revision of the text
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 21 April 2006
Reasons for updating
- Change to drug interactions
Updated on 20 January 2006
Reasons for updating
- New PIL for medicines.ie
Updated on 06 December 2005
Reasons for updating
- Change to section 6.1 - List of excipients
- Change to section 6.2 - Incompatibilities
- Change to section 6.3 - Shelf life
- Change to section 6.4 - Special precautions for storage
- Change to section 6.5 - Nature and contents of container
- Change to section 6.6 - Special precautions for disposal and other handling
Legal category:Product subject to medical prescription which may not be renewed (A)
Updated on 30 June 2003
Reasons for updating
- New SPC for medicines.ie
Legal category:Product subject to medical prescription which may not be renewed (A)