Disopyramide Rifampin

Drugs that may affect disopyramide include antiarrhythmics, beta blockers, cisapride, clarithromycin, erythromycin, fluoroquinolones, hydantoins, quinidine, thioridazine, rifampin, verapamil, and ziprasidone. Drugs that may be affected by disopyramide include quinidine, anticoagulants, and digoxin. 

Rifampin is known to induce the hepatic microsomal enzymes that metabolize various drugs such as acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, beta blockers, chloramphenicol, clofibrate, oral contraceptives, corticosteroids, cyclosporine, disopyramide, estrogens, hydantoins, mexiletine, quinidine, sulfones, sulfonylureas, theophyllines, tocainide, verapamil, digoxin, enalapril, morphine, nifedipine, ondansetron, progestins, protease inhibitors, buspirone, delavirdine, doxycycline, fluoroquinolones, losartan, macrolides, sulfonylureas, tacrolimus, thyroid hormones, TCAs, zolpidem, zidovudine, and ketoconazole. The therapeutic effects of these drugs may be decreased. 

In the presence of phenytoin, the metabolism of disopyramide is increased (reducing its effective concentration) and the accumulation of its metabolites is also increased, thereby increasing the probability of anticholinergic adverse effects. Rifampin also stimulates the hepatic metaboUsm of disopyramide, reducing its plasma concentration. 

Drug Interactions Other antihypertensive agents Carbamazepine (vasodilators, ACE inhibitors, Rifampin diuretics, and beta-blockers) Phenobarbital Digoxin Cyclosporine Disopyramide Theophylline Flecainide Inhalation anesthetics Quinidine Neuromuscular blocking agents Cimetidine Lithium ... 

CYP2C8 <5 1-2 Disopyramide Amiodarone Clozapine Diclofenac Fluvastatin Nicardipine Paclitaxel Retinoic acid Rosiglitazone Torsemide Repaglinide Amiodarone Celecoxib Felodipine Nicardipine Fluoxetine Ketoconazole Ritonavir Indinavir Troglitazone Zafirlukast Retinoic acid Clotrimazole Phenobarbital Dexamethasone Gemfibrozil Rifampin Phenytoin Ritonavir... 

Staum JM. En me inductim rifampin-disopyramide interaction. DICP Arm Pharmacoffter (1990)24,701-3. 

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