rifampin and Arrhythmias--Cardiac

A 33-year-old woman with congenital heart disease and atrial and ventricular arrhythmias, managed over the long term with an implantable cardioverter defibrillator, epicardial pacing system, and amiodarone, experienced an increase in palpitations and a shock from her defibrillator. Evaluation revealed decreases in amiodarone and desethylamiodarone serum concentrations from previous levels. Rifampin had been added to her therapy 5 weeks earlier. Increases in amiodarone and desethylamiodarone concentrations were observed after an increase in the amiodarone dosage and discontinuation of rifampin. The time course suggested that the addition of rifampin led to reductions in serum concentrations of both the drug and metabolite.

Topics: Adult; Amiodarone; Antibiotics, Antitubercular; Arrhythmias, Cardiac; Defibrillators, Implantable; Female; Heart Defects, Congenital; Humans; Rifampin

Topics: Arrhythmias, Cardiac; Benzeneacetamides; Drug Interactions; Humans; Male; Middle Aged; Piperidines; Rifampin

Topics: Aged; Arrhythmias, Cardiac; Drug Interactions; Humans; Male; Quinidine; Rifampin

Serum drug concentration data from the first of the two patients described herein suggest that rifampin may directly increase the metabolism of quinidine and thereby negate the influence of quinidine on the serum digoxin concentration (SDC). Data on the second patient suggest that rifampin may directly increase the metabolism of digoxin producing lower SDC values. In both cases, the discontinuation of rifampin therapy appears to have allowed reversion toward prerifampin metabolism of both quinidine and digoxin.

Topics: Aged; Arrhythmias, Cardiac; Digoxin; Drug Interactions; Drug Therapy, Combination; Female; Humans; Kinetics; Middle Aged; Quinidine; Rifampin; Tuberculosis, Pulmonary