Comparative clinical profiles of triazolam versus other shorter-acting hypnotics

The efficacy, safety, and performance of triazolam was compared with those of other shorter-acting hypnotics acting on the gamma-aminobutyric acid (GABA) receptor--zopiclone, zolpidem, midazolam, brotizolam, temazepam, lormetazepam, and loprazolam. In all, 5506 patients participated in 38 clinical and epidemiologic studies, of whom 2462 were treated with triazolam in parallel-design and crossover studies. To provide clinically relevant comparisons, only studies using comparator agents in doses equipotent to the triazolam doses were included. Two general findings emerged. First, "serious" central nervous system side effects, such as excitement and violence, were not demonstrated for any of the hypnotic agents, including triazolam. Other central nervous system side effects, such as depression and irritability, were reported with equal frequencies for all the hypnotics reviewed. Rebound insomnia, reported intermittently with most of these agents, was short-lived and not clinically significant. So-called early morning insomnia was noted only once and does not appear to be a valid clinical entity. Daytime anxiety was not observed in large numbers of triazolam-treated subjects studied, which is contrary to claims that the drug is anxiogenic. Second, a remarkable similarity was found among all of these shorter-acting agents in terms of efficacy, side effects, and performance-related effects. This was particularly of note for zopiclone and zolpidem. Although claims have been made suggesting differences, evaluation of the studies herein showed that these nonbenzodiazepine hypnotics were indistinguishable from triazolam and other benzodiazepine hypnotics in their clinical and pharmacologic activity. Thus, different chemical structures did not a priori predict different clinical profiles when drugs share a similar mechanism of action.