Clinical and biochemical comparison of clorazepate and diazepam

Abstract

SYSNOPSISClorazepate and diazepam were compared with respect to clinical effectiveness and concentrations of benzodiazepine compounds in plasma in 15 severely anxious outpatients. Each patient was studied in a double blind trial incorporating two-week periods of the two drugs and of placebo. The doses were almost equimolar—5 mg diazepam or 7·5 mg clorazepate three times daily. Clinical progress was assessed by visual analogue scales and by the Symptom Rating Test. Psychopathology scores were highest at the end of the placebo periods, and lowest at the end of the clorazepate periods, regardless of the order of treatments. After diazepam, both diazepam and N-desmethyldiazepam (nordiazepam) were detected in blood, and after clorazepate, only N-desmethyldiazepam was detected. N-Desmethyldiazepam concentrations were higher after clorazepate. Clinical progress was apparently related to the concentration of N-desmethyldiazepam in plasma.