No effect of imidafenacin, a novel antimuscarinic drug, on digoxin pharmacokinetics in healthy subjects

Drug Metab Pharmacokinet. 2008;23(2):95-100. doi: 10.2133/dmpk.23.95.

Abstract

Plasma digoxin concentrations are increased by the coadministration of anticholinergic drugs, such as propantheline, which decrease gastrointestinal motility. The present study evaluated the effect of imidafenacin, a novel anticholinergic drug, on the pharmacokinetics of digoxin. The effect of imidafenacin on the pharmacokinetics of digoxin was examined in 14 healthy Japanese male subjects in a single-centre, open-label, randomized, two-way crossover study. Subjects received a daily oral dose of digoxin 0.25 mg on days 1 and 2 and digoxin 0.125 mg on days 3 to 8 (period 1). Following a 2-week washout period, digoxin was administered orally for 8 days in a similar manner (period 2). A twice daily dose of imidafenacin 0.1 mg was concomitantly administered with digoxin for 8 days either in period 1 or 2. The geometric mean ratios [GMR] (90% confidence intervals [CIs]) for digoxin C(max) and AUC(0-24) (with/without imidafenacin) at steady state were 0.88 (0.74, 1.04) and 1.00 (0.90, 1.10), respectively. The 90% CIs of GMR for digoxin trough concentration, urinary excretion amount and renal clearance at steady state fell within the range of 0.8 to 1.25. The steady-state pharmacokinetics of digoxin is not affected by concomitant administration of imidafenacin in healthy subjects.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Cross-Over Studies
  • Digoxin / pharmacokinetics*
  • Drug Interactions
  • Humans
  • Imidazoles / pharmacology*
  • Male
  • Muscarinic Antagonists / pharmacology*

Substances

  • Imidazoles
  • Muscarinic Antagonists
  • Digoxin
  • imidafenacin