[Effect of propafenone on the pharmacokinetics of digoxin administered orally: a study in healthy volunteers].

It is well known that many cardiovascular drugs affect digoxin kinetics, but nothing is defined on propafenone-digoxin interaction. To clarify this problem, we studied digoxin kinetics in 8 healthy men, who received digoxin oral dose (0.50 mg) in the control state and again during maintenance therapy with propafenone (150 mg q.i.d.). Statistically significant changes were observed during propafenone in a number of digoxin kinetic indexes: a rise in peak serum digoxin concentration (4.30 vs 3.07 ng/ml - p less than 0.005), in area under the serum-digoxin concentration curve (4 h: 520.4 vs 368.9; 10 h: 789.6 vs 621.3 ng X min/ml - p less than 0.005; 24 h: 1187.6 vs 954.7 ng X min/ml - p less than 0.05) and urinary excretion of digoxin (277.7 vs 203.5 mcg - p less than 0.005). Renal digoxin clearance was not affected by propafenone. We conclude that propafenone interact kinetically with digoxin in healthy subjects, perhaps increasing digoxin bioavailability.