Comparison of controlled-release diazepam capsules and placebo in patients in general practice

A multi-centre, randomized double-blind parallel study was carried out to compare the efficacy and tolerance of a single daily dose of controlled-release (CR) capsules of diazepam (10 mg and 15 mg) with placebo under conditions close to those of general practice. All patients between 16 and 60 years of age, presenting an anxiety syndrome as a result of neurotic disturbance, for whom benzodiazepine treatment was indicated for at least 3 weeks, were accepted for the study. The results from 231 patients (119 on placebo, 55 on 10 mg and 57 on 15 mg diazepam) were analyzed after 1 and 3 weeks of treatment. Complaints were found to have improved after 1 week and 3 weeks in the controlled-release diazepam groups whereas the corresponding results with placebo were clearly less favourable. After 1 week, and even more strikingly after 3 weeks, evaluation of the general effects of treatment showed better results with diazepam than with placebo. The obviously higher rate of drop-outs on placebo confirmed its less reliable effect. The controlled-release capsules were well tolerated and notably better than placebo. The most frequent side-effect reported on diazepam was fatigue, and this was probably due to a relative overdosage from use of a standardized dose throughout treatment. Other reported side-effects could not definitely be ascribed to the drug. At the end of a week, successful results were achieved in 48.2% of the patients on controlled-release diazepam compared with only 14.3% of those on placebo. After 3 weeks, these figures were 73.2% and 30.3%, respectively.