Digoxin pharmacokinetics and spirapril, a new ace inhibitor

As concurrent use of digoxin with the novel ACE inhibitor spirapril should be common, potential for spirapril to affect steady-state digoxin kinetics was studied. Fifteen healthy white male volunteers aged 22-42 and weighing 135-225 lbs took digoxin tablets 0.25 mg every 12 hours for 5 weeks. In crossover design, each also received spirapril or matching placebo capsules during weeks 1 and 2, or 4 and 5. Dosage of spirapril was increased from 12 mg to 48 mg once daily. Spirapril produced no significant effect on mean (+/- SD) serum digoxin concentration in the steady state, area under curve for 12 hours, peak digoxin level, time to peak, or urinary digoxin excretion over 12 hours. No change in renal or whole body digoxin clearance was seen. Unlike some other cardiovascular drugs, spirapril does not alter steady-state digoxin kinetics in healthy adults.