Effect of tenidap sodium on digoxin pharmacokinetics in healthy young men

1. The effects of tenidap sodium and placebo on digoxin pharmacokinetics were compared in 14 healthy young men, in a double-blind, parallel-group study lasting for 24 days. 2. Subjects were administered digoxin alone for the first 10 days and digoxin plus tenidap 120 mg day-1 or placebo for the remaining 14 days. 3. Changes in the means between day 10 (digoxin monotherapy) and day 24 (combined therapy) for renal clearance, area under the plasma concentration-time curve during the dosing interval, and the minimum and maximum plasma digoxin concentrations did not differ significantly between the tenidap and placebo groups. There was a small but statistically significant increase (0.5 h) in the time taken to reach maximum plasma digoxin concentration following 14 days' continuous tenidap co-administration compared with placebo, but this was not considered to be clinically meaningful. 4. Co-administration of tenidap and digoxin was well tolerated. No subject withdrew from the study during combination treatment. Treatment-related adverse events were of mild to moderate severity and were reported by four subjects on digoxin monotherapy, four on tenidap and digoxin, and by two on digoxin and placebo. Those reported by the tenidap group predominantly affected the gastrointestinal system and were mild in severity. There were no reports of laboratory test abnormalities or cardiovascular abnormalities related to combined digoxin and tenidap administration. 5. The results of this study indicate that, in healthy young men, co-administration of tenidap with digoxin does not have any apparent clinically significant effects on the pharmacokinetic profile of digoxin, and the treatment is well tolerated.