We evaluated the effect of quinidine on digoxin pharmacokinetics in six patients with severe renal failure. Quinidine reduced the total body clearance of digoxin from 1.87 to 1.06 l/hour (p < 0.001), and prolonged the digoxin half-life of elimination from 5.20 to 9.61 days (p < 0.01). The digoxin volume of distribution was unchanged. Renal clearance of digoxin was negligible; thus, the decrease in total body clearance was due to a decrease in the nonrenal clearance of digoxin. The mean trough serum concentrations of quinidine ranged from 1.0 to 3.0 μg/ml. We conclude that in patients with chronic renal failure, the dose of digoxin should be decreased by 50% if quinidine therapy is initiated.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)