When antacids or antisecretory drugs are used concomitantly, they should not be taken simultaneously with oral formulations of Motilium (domperidone base), i.e., they should be taken after meals and not before meals.
Co-administration with levodopa
Although no dosage adjustment of levodopa is deemed necessary, an increase (maximum of 30% - 40%) of plasma concentration has been observed when domperidone was taken concomitantly with levodopa.The main metabolic pathway of domperidone is through CYP3A4. In vitro data suggest that the concomitant use of drugs that significantly inhibit this enzyme may result in increased plasma levels of domperidone. Increased risk of occurrence of QT interval prolongation, due to pharmacodynamic and/or pharmacokinetic interactions.
Concomitant use of the the following substances is contraindicated
QTc-prolonging medicinal products (risk of torsades de points) • anti-arrhythmics class IA (e.g., disopyramide, hydroquinidine, quinidine) • anti-arrhythmics class III (e.g., amiodarone, dofetilide, dronedarone, ibutilide, sotalol) • certain antipsychotics (e.g., haloperidol, pimozide, sertindole)• certain antidepressants (e.g., citalopram, escitalopram)• certain antibiotics (e.g., erythromycin, levofloxacin, moxifloxacin, spiramycin)• certain antifungal agents (e.g., fluconazole, pentamidine)• certain antimalarial agents (in particular halofantrine, lumefantrine) • certain gastro-intestinal medicines (e.g., cisapride, dolasetron, prucalopride) • certain antihistaminics (e.g., mequitazine, mizolastine)• certain medicines used in cancer (e.g., toremifene, vandetanib, vincamine)• certain other medicines (e.g., bepridil, diphemanil, methadone)(see section 4.3).Potent CYP3A4 inhibitors (regardless of their QT-prolonging effects), i.e.,:• protease inhibitors (e.g. ritonavir, saquinaver, telaprevir)• systemic azole antifungals (e.g. itraconazole, ketoconazole, posaconazole, voriconazole)• certain macrolide antibiotics (e.g., clarithromycin, telithromycin) (see section 4.3).
Concomitant use of the following substances is not recommended
• Moderate CYP3A4 inhibitors i.e., diltiazem, verapamil and some macrolides.
Concomitant use of the following substances requires caution with use
Caution with bradycardia and hypokalaemia-inducing drugs, as well as with the following macrolides involved in QT interval prolongation: azithromycin and roxithromycin (clarithromycin is contraindicated as it is a potent CYP3A4 inhibitor).The above list of substances is representative and not exhaustive.