|
In post-marketing experience tumor lysis syndrome (TLS) has been reported very rarely in patients with hematological malignancies following the use of dexamethasone alone or in combination with other chemotherapeutic agents. Patients at high risk of TLS should be monitored closely and appropriate precautions taken.
The lowest effective dose of corticosteroid should be used to control the condition under treatment for the minimum period. Frequent patient review is required to appropriately titrate the dose against disease activity.
Patients currently on corticosteroid therapy or those who have been on such treatment within the previous year may require special control measures if involved in anaesthesia, surgical procedures and other stress.
Withdrawal of corticosteroids should always be gradual and related to the duration of use. Too rapid a reduction of dexamethasone dosage following prolonged treatment can lead to acute adrenal insufficiency, hypotension and death.
A withdrawal syndrome may occur. Withdrawal may result in acute rebound exacerbation of disease, acute adrenocortical insufficiency, polyarteritis. Symptoms of this may include fever, myalgia, arthralgia, rhinitis, conjunctivitis, painful itchy skin nodules and loss of weight.
In patients who have received more than physiological doses of systemic corticosteroids (approximately 1 mg dexamethasone (equivalent to 1.2 mg dexamethasone phosphate)) for greater than 3 weeks, withdrawal should not be abrupt. How dose reduction should be carried out depends largely on whether the disease is likely to relapse as the dose of systemic corticosteroids is reduced. Clinical assessment of disease activity may be needed during withdrawal. If the disease is unlikely to relapse on withdrawal of systemic corticosteroids but there is uncertainty about HPA suppression, the dose of systemic corticosteroid may be reduced rapidly to physiological doses. Once a daily dose of 1 mg dexamethasone is reached, dose reduction should be slower to allow the HPA-axis to recover.
Abrupt withdrawal of systemic corticosteroid treatment, which has continued up to 3 weeks is appropriate if it is considered that the disease is unlikely to relapse. Abrupt withdrawal of doses up to 6 mg of dexamethasone (equivalent to 7.3 mg dexamethasone phosphate) for 3 weeks is unlikely to lead to clinically relevant HPA-axis suppression, in the majority of patients. In the following patient groups, gradual withdrawal of systemic corticosteroid therapy should be considered even after courses lasting 3 weeks or less:
• Patients who have had repeated courses of systemic corticosteroids, particularly if taken for greater than 3 weeks,
• When a short course has been prescribed within one year of cessation of long-term therapy (months or years),
• Patients who may have reasons for adrenocortical insufficiency other than exogenous corticosteroid therapy,
• Patients receiving doses of systemic corticosteroid greater than 6 mg daily of dexamethasone,
• Patients repeatedly taking doses in the evening.
Adrenal suppression: adrenal cortical atrophy develops during prolonged therapy and may persist for years after stopping treatment. Withdrawal of corticosteroids after prolonged therapy must, therefore, be gradual to avoid acute adrenal insufficiency, being tapered off over weeks or months according to the dose and duration of treatment. During prolonged therapy any intercurrent illness, trauma or surgical procedure will require a temporary increase in dosage; if corticosteroids have been stopped following prolonged treatment they may need to be temporarily re-introduced.
Patients should carry 'Steroid treatment' cards which give clear guidance on the precautions to be taken to minimise risk and which provide details of prescriber, drug, dosage and the duration of treatment.
There is a lack of evidence to support the prolonged use of corticosteroids in septic shock. Although they may be of value in the early treatment, the overall survival may not be influenced.
Severe anaphylactoid reactions have occurred after administration of parenteral corticosteroids, such as glottis oedema, urticaria and bronchospasm, particularly in patients with a history of allergy. Appropriate precautions should be taken prior to administration. If such an anaphylactoid reaction occurs, the following measures are recommended: immediate slow intravenous injection of adrenaline, intravenous administration of aminophylline, and artificial respiration if necessary.
The slower rate of absorption after intramuscular injection should be noted.
Intra-articular corticosteroids are associated with a substantially increased risk of an inflammatory response in the joint, particularly a bacterial infection introduced with the injection. Great care is required and all intra-articular corticosteroid injections should be undertaken in an aseptic environment. Charcot-like arthropathies have been reported particularly after repeated injections.
Prior to intra-articular injection the joint fluid should be examined to exclude a septic process. A marked increase in pain, accompanied by local swelling, further restriction of joint motion, fever and malaise are suggestive of septic arthritis. If this complication occurs and sepsis is confirmed, appropriate antimicrobial therapy should be commenced.
Patients should be impressed strongly with the importance of not overusing joints in which symptomatic benefit has been obtained, but the inflammatory process remains active.
Corticosteroids may mask some signs of infection, decrease resistance and inhibit localisation of infection. Suppression of the inflammatory response and the immune function increases the susceptibility to infections and their severity. The clinical presentation may be atypical and serious infections, such as septicaemia and tuberculosis, may be masked and may reach an advanced stage before being recognised.
Live vaccines should not be given to individuals with impaired immune responsiveness. The antibody response to other vaccines may be diminished.
Chickenpox is of particular concern since this normally minor illness may be fatal in immunosuppressed patients. Patients (or parents of children) without a definite history of chicken pox should be advised to avoid close personal contact with chickenpox or herpes zoster and if exposed they should seek urgent medical attention. Passive immunisation with varicella zoster immunoglobin (VZIG) is needed by exposed non-immune patients who are receiving systemic dexamethasone or who have received it during the previous 3 months; this should be given within 10 days of exposure to chickenpox. If a diagnosis of chickenpox is confirmed, the illness warrants specialist care and urgent treatment. Dexamethasone should not be stopped and the dose may need to be increased.
Measles can have a more serious or even fatal course in immunosuppressed patients. In such children or adults, particular care should be taken to avoid exposure to measles. If exposed, prophylaxis with pooled immunoglobin may be indicated. Exposed patients should be advised to seek medical advice without delay. Prolonged use of corticosteroids may produce posterior subcapsular cataracts, glaucoma with possible damage to the optic nerve and may enhance the establishment of secondary ocular infections due to fungi or viruses.
False negative results may occur with the nitroblue tetrazolium test for bacterial infection.
Extreme caution should be exercised in the treatment of patients with the following conditions and frequent patient monitoring is necessary:
• Liver failure, chronic renal failure, renal insufficiency, gastro-intestinal ulceration, congestive heart failure, hypertension, epilepsy, migraine and patients with Cushing's syndrome
• Osteoporosis, since coticosteroids increase calcium excretion. Post-menopausal women are at particular risk.
• Latent tuberculosis, as corticosteroids can cause reactivation.
• Hypothyroidism or cirrhosis, because such patients often show an exaggerated response to corticosteroids.
• Certain parasitic infestations, in particular amoebiasis. Latent amoebiasis, as corticosteroids may cause reactivation. Prior to treatment, amoebiasis should be ruled out in any patient with unexplained diarrhoea or who has recently spent time in the tropics.
• Ocular herpes simplex, because corticosteroids may cause corneal perforation.
• Incomplete statural growth since glucocorticoids on prolonged administration may accelerate epiphyseal closure.
• In the treatment of conditions such as tendinitis or tenosynovitis care should be taken to inject into the space between the tendon sheath and the tendon as cases of ruptured tendon have been reported.
Corticosteroids should also be used with caution in patients with diabetes mellitus (or a family history of diabetes), affective disorders, glaucoma (or a family history of glaucoma), or previous corticosteroid-induced myopathy.
The use of corticosteroids in the presence of other disorders or of drugs with specific actions (e.g hypoglycaemics), impinging on the effects of corticosteroids will result in imbalance of control.
Dexamethasone has been used 'off–label' to treat and prevent chronic lung disease in preterm infants. Clinical trials have shown a short term benefit in reducing ventilator dependence but no long term benefit in reducing time to discharge, the incidence of chronic lung disease or mortality. Recent trials have suggested an association between the use of dexamethasone in preterm infants and the development of cerebral palsy. In view of this possible safety concern, an assessment of the risk:benefit should be made on an individual patient basis.
In view of multiple adverse effects noted in premature infants who received dexamethasone, the risks in many cases outweigh the benefits. Very serious consideration should therefore be given before dexamethasone is administered to such patients.
Available evidence suggests long-term neurodevelopmental adverse events after early treatment (< 96 hours) of premature infants with chronic lung disease at starting doses of 0.25 mg/hg twice daily.
Prolonged use in children may lead to growth retardation. Some recovery may occur on discontinuing therapy.
The common adverse effects of systemic corticosteroids may be associated with more serious consequences in old age, especially osteoporosis, hypertension, hypokalaemia, diabetes, susceptibility to infection and thinning of the skin. Close clinical supervision is required to avoid life-threatening reaction.
Corticosteroids should not be used for the management of head injury or stroke because it is unlikely to be of any benefit and may even be harmful.
Patients and/or carers should be warned that potentially severe psychiatric adverse reactions may occur with systemic steroids (see section 4.8). Symptoms typically emerge within a few days or weeks of starting the treatment. Risks may be higher with high doses/systemic exposure (see also section 4.5 pharmacokinetic interactions that can increase the risk of side effects), although dose levels do not allow prediction of the onset, type, severity or duration of reactions. Most reactions recover after either dose reduction or withdrawal, although specific treatment may be necessary.
Patient/carers should be encouraged to seek medical advice if worrying psychological symptoms develop, especially if depressed mood or suicidal ideation is suspected. Patients/carers should also be alert to possible psychiatric disturbances that may occur either during or immediately after dose tapering/withdrawal of systemic steroids, although such reactions have been reported infrequently.
Particular care is required when considering the use of systemic corticosteroids in patients with existing or previous history of severe affective disorders in themselves or in their first degree relatives. These would include depressive or manic-depressive illness and previous steroid psychosis.
The results of a randomized, placebo-controlled study suggest an increase in mortality if methylprednisolone therapy starts more than two weeks after the onset of Acute Respiratory Distress Syndrome (ARDS). Therefore, treatment of ARDS with corticosteroids should be initiated within the first two weeks of onset of ARDS.
This medicinal product contains less than 1 mmol sodium (23 mg) per 2ml, i.e. essentially 'sodium-free'.
The excipient, sodium sulphite may rarely cause severe hypersensitivity reactions and bronchospasm.
The vial stopper contains dry natural rubber (a derivative of latex), which may cause allergic reactions.
|