Siamidine Drug Interactions

Drug metabolized by hepatic microsomal enzymes (Cytochrome P450): Cimetidine inhibits cytochrome P450 (CYP) , including CYP1A2, CYP2C19, CYP2C9, CYP2D6, CYP2E1, CYP3A4, CYP3A3 and CYP2C18. Inhibition of these enzymes may result in increased plasma levels of certain drugs including coumarin anticoagulants (e.g., warfarin), phenytoin, propanolol, some benzodiazepines, lidocaine, metronidazole, triamterene, some tricyclic antidepressants, and theophylline.
Antiarrhythmic agent: Concurrent use of Cimetidine and antiarrhythemic agent such as disopyramide, dofetilide, procainamide, quinidine, sotalol may result in prolong QT interval and increase the risk of life-threatening cardiac arrhythmias, including torsades de pointes cardiac arrest.
Antifungal: Cimetidine alters gastric pH and may decrease the absorption of some azole antifungals such as ketoconazole. If concomitant therapy with such drugs is needed, they should be administered at least 2 hours prior to Cimetidine administration.
Anticoagulant: Concurrent use of Cimetidine and warfarin may result in an increased risk of bleeding. If the drugs must be administered concurrently, prothrombin time should be carefully monitored and dosage adjustment of the anticoagulant may be necessary.
Myelosuppressive drugs: Cimetidine may potentiate the myelosuppressive effects (e.g. neutropenia, agranulocytosis) of myelosuppressive drugs such as alkylating agents (e.g. carmustine), antimetabolites or therapies (e.g, radiation).
Film-coated tablet: Antacid: Antacids may reduce the absorption of Cimetidine. To prevent any potential interaction, antacids should probably be taken 1 hour before or after Cimetidine in the fasting state, or 1 hour after Cimetidine is taken with food.