Effect of nifedipine on digoxin kinetics in healthy subjects.

Verapamil has been shown to reduce total-body digoxin clearance by 35% due to impairments of both renal and extrarenal clearances. Our study was undertaken to evaluate the influence of the related calcium antagonist nifedipine on single-dose kinetics. Nifedipine increased extrarenal clearance of digoxin from 1.09 +/- 0.30(SD) to 1.45 +/- 0.23 ml/min/kg (P less than 0.05) and reduced the total urinary recovery of the drug from 69.2% +/- 5.9(SD) to 64.3% +/- 5.2 (P less than 0.05). There were no significant changes in renal digoxin clearance, distribution, or biological half-life or in digoxin distribution volumes during nifedipine coadministration.