N-monodesmethyldiltiazem is the predominant metabolite of diltiazem in the plasma of young and elderly hypertensives

Br J Clin Pharmacol. 1987 Aug;24(2):185-9. doi: 10.1111/j.1365-2125.1987.tb03160.x.


1 Twelve young (ages 30-39 years) and twelve elderly (ages 65-83 years) hypertensives were administered diltiazem twice daily for 2 weeks at doses up to 240 mg day-1. 2 Plasma was analysed for diltiazem, N-monodesmethyldiltiazem, and desacetyldiltiazem concentrations after a single 10 min intravenous infusion of 21.8 mg diltiazem HCl on day 1 and after the morning oral dose of 120 mg diltiazem base on day 14. 3 N-monodesmethyldiltiazem accumulated to higher plasma concentrations than desacetyldiltiazem at steady state on day 14 in both age groups. 4 Prolongation of plasma diltiazem half-life occurred after 2 weeks of oral diltiazem therapy in both age groups. 5 There were no significant differences between the young and elderly with regard to half-life, area under the curve, and the peak and trough plasma concentrations of diltiazem, N-monodesmethyldiltiazem, and desacetyldiltiazem; systemic clearance and volume of distribution of diltiazem were also similar in both groups.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / metabolism*
  • Biotransformation
  • Diltiazem / analogs & derivatives*
  • Diltiazem / blood
  • Diltiazem / metabolism*
  • Female
  • Half-Life
  • Humans
  • Hypertension / metabolism*
  • Kinetics
  • Male


  • deacetyldiltiazem
  • Diltiazem
  • N-monodemethyldiltiazem