The influence of steady-state ciprofloxacin on the pharmacokinetics and pharmacodynamics of a single dose of diazepam in healthy volunteers

Eur J Clin Pharmacol. 1993;44(4):365-7. doi: 10.1007/BF00316474.


The effects of pretreatment with a seven day course of ciprofloxacin on pharmacokinetics and pharmacodynamics of an intravenous (5 mg) dose of diazepam were investigated in a group of 12 healthy volunteers in a double-blind placebo-controlled crossover study. Ciprofloxacin pretreatment significantly reduced diazepam CL (without ciprofloxacin: 19.5 ml.h-1 kg-1; with ciprofloxacin: 12.3 ml.h-1 kg-1). Diazepam t1/2 was also prolonged (without ciprofloxacin: 36.7 h; with ciprofloxacin: 71.1 h), but volume of distribution was unaltered (without ciprofloxacin: 1.1; with ciprofloxacin: 1.1 However, no significant changes were detected in psychometric tests of digit symbol substitution, tapping rate and short memory, as well as levels of concentration, vigilance and tension measured by visual analogue scales.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Analysis of Variance
  • Chromatography, High Pressure Liquid
  • Ciprofloxacin / pharmacology*
  • Diazepam / administration & dosage
  • Diazepam / pharmacokinetics*
  • Double-Blind Method
  • Drug Interactions
  • Female
  • Humans
  • Injections, Intravenous
  • Male
  • Metabolic Clearance Rate / drug effects
  • Neuropsychological Tests
  • Psychometrics


  • Ciprofloxacin
  • Diazepam