Troleandomycin-triazolam interaction in healthy volunteers: pharmacokinetic and psychometric evaluation

Eur J Clin Pharmacol. 1987;32(4):389-93. doi: 10.1007/BF00543975.


Seven healthy volunteers received a single oral dose of triazolam 0.25 mg after 7 days on troleandomycin 2 g/day p.o. or placebo in a double-blind cross-over study. Plasma triazolam and psychometric and memory tests (including Critical Flicker Fusion threshold, Choice Reaction Time, Digit Symbol Substitution and Self-Rating Scales) were assessed at regular intervals after the final treatment. Troleandomycin was found to prolong the psychomotor impairment and amnesia produced by triazolam. There was a significant enhancement of the AUC, the peak concentration and the delay to tmax of triazolam after 7 days treatment with troleandomycin compared to placebo. Thus, there is a pharmacokinetic interaction, and the combination of triazolam and troleandomycin should be avoided or the dose of triazolam should be adjusted. The most likely mechanism is a diminished hepatic first-pass effect, and a decrease in the apparent oral clearance of triazolam.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Drug Interactions
  • Humans
  • Kinetics
  • Liver / metabolism
  • Male
  • Memory / drug effects
  • Psychomotor Performance / drug effects*
  • Triazolam / metabolism
  • Triazolam / pharmacology*
  • Troleandomycin / pharmacology*


  • Triazolam
  • Troleandomycin