On the dose equivalence of flurazepam and triazolam

Flurazepam (30 mg), triazolam (0.5 mg) and placebo were given in the morning to 6 normal volunteers in a double-blind crossover study. Subjects were evaluated by a large battery of psychophysiological tests before and 1 and 5 hours after drug administration. Triazolam was significantly more sedative than flurazepam and both were significantly different from placebo. Slope-ratio assay analysis of the results from the present study pooled with those from a similar previous study (C. Gorenstein and V. Gentil, Psychopharmacology, 80: 376-379, 1983) indicated that these doses are non-equivalent. We suggest that dose-equivalence studies based on the present method should be carried out early in the development of new hypnotic drugs.