A long-acting benzodiazepine is more effective in divided doses

To the Editor: On a pharmacokinetic basis and as a function of their plasma half-lives, benzodiazepines have been divided into two groups; short-acting (such as oxazepam, lorazepam, temazepam, and triazolam) and long-acting (such as chlordiazepoxide, diazepam, clorazepate, and medazepam).1 Short-acting benzodiazepines are frequently recommended in the treatment of insomnia, whereas long-acting compounds are thought to be preferable for the treatment of chronic anxiety, with the possibility of once-a-day administration. Actually, no study has proved that daily administration of a single dose of a long-acting benzodiazepine is as effective as divided doses in the treatment of anxiety disorders. Therefore, we performed. © 1984, Massachusetts Medical Society. All rights reserved.