THE INFLUENCE OF STEADY-STATE CIPROFLOXACIN ON THE PHARMACOKINETICS AND PHARMACODYNAMICS OF A SINGLE-DOSE OF DIAZEPAM IN HEALTHY-VOLUNTEERS

The effects of pretreatment with a seven day course of ciprofloxacin o n 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 pretre atment 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 l.kg-1; with ciprofloxacin: 1.1 l.kg-1). However, no significant changes were detected in psychometric tests of digit symbol substituti on, tapping rate and short memory, as well as levels of concentration, vigilance and tension measured by visual analogue scales.