Rifampicin Disopyramide

DISOPYRAMIDE ANTIBIOTICS-RIFAMPICIN Disopyramide levels are 1 by rifampicin Rifampicin induces hepatic metabolism of disopyramide Watch for poor response to disopyramide check serum levels if necessaiy... 

ANTIARRHYTHMICS - disopyramide, propafenone 2. ANTIBIOTICS-chloramphenicol, doxycycline, metronidazole, rifampicin, telithromycin 3. ANTICANCER AND IMMUNOMODULATING DRUGS - carmustine, cidosporin, corticosteroids, doxorubicin, etoposide, ima-tinib, lomustine, paditaxel, tacrolimus, tamoxifen, toremifene, vinca alkaloids 4. ANTICOAGULANTS - ORAL 5. ANTI-... 

Clinically important, potentially hazardous interactions with amiodarone, astemizole, bepridil, carbamazepine, chloroquine, cisapride, clarithromycin, dihydroergotamine, disopyramide, ergotamine, grapefruit juice, halofantrine, haloperidol, itraconazole, ketoconazole, methadone, moxifloxacin, phenobarbital, phenytoin, pimozide, procainamide, quinidine, rifampicin, ritonavir, sotalol, St John s wort, telithromycin, terfenadine, voriconazole... 

The plasma levels of disopyramide can be reduced by rifampicin. Clinical evidence... 

After taking rifampicin for 14 days the plasma levels of disopyramide were approximately halved in 11 patients with tuberculosis who had taken a single 200- or 300-mg dose of disopyramide. The disopyramide AUC was reduced by about two-thirds and the half-life was reduced from 5.9 to... 

The most probable explanation is that rifampicin (a well-known enzyme inducer) increases the metabolism of the disopyramide by the liver so that it is cleared from the body much more quickly. 

Information seems to be limited to these studies, but they indicate that the dosage of disopyramide will need to be increased in most patients taking rifampicin. 

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