Pharmacology, efficacy, and adverse effects of halazepam, a new benzodiazepine

Halazepam is a new benzodiazepine derivative that is molecularly similar to chlordiazepoxide and diazepam. Animal studies indicated that halazepam produces sedative and antianxiety effects with less toxicity than chlordiazepoxide or diazepam. Computer EEG and somatosensory evoked potential studies demonstrated that halazepam has a significant effect on the EEG, characteristic of changes that occur with benzodiazepines. In initial clinical studies, halazepam exhibited not only anxiolytic properties but also reduced symptoms of depression and had a therapeutic effect on epilepsy. In preliminary, uncontrolled clinical trials, halazepam was effective in ameliorating anxiety and tension in alcoholic and acute schizophrenic patients, with few adverse effects. Later double-blind studies generally demonstrated that halazepam is significantly superior to placebo in alleviating symptoms of anxiety and tension. Most comparative studies indicate that halazepam is equal to or more effective than diazepam with a lower frequency of side effects. Halazepam does not increase hostility and aggression, as chlordiazepoxide and diazepam have been shown to do, and it is effective in both situational and characterologic anxiety. Drowsiness and slight dry mouth are the only side effects reported in more than isolated instances, although geriatric patients may frequently become ataxic with higher doses.