Halazepam is a benzodiazepine derivative that was marketed under the brand names Paxipam in the United States, Alapryl in Spain,[1] and Pacinone in Portugal.[2]
Halazepam was used for the treatment of anxiety.
Adverse effects include drowsiness, confusion, dizziness, and sedation. Gastrointestinal side effects have also been reported including dry mouth and nausea.
Pharmacokinetics and pharmacodynamics were listed in Current Psychotherapeutic Drugs published on June 15, 1998 as follows:[3]
| Onset of action | Intermediate to slow | |
| Plasma half life | 14 hr for parent drug and 30-100 hr for its metabolite | |
| Peak plasma levels | 1-3 hr for parent drug and 3-6 hf for its metabolite | |
| Metabolism | Metabolized into desmethyldiazepam and 3-hydroxyhalazepam (in the liver) | |
| Excretion | Excreted through kidneys | |
| Protein binding | 98% bound to plasma protein |
Halazepam is classified as a schedule 4 controlled substance with a corresponding code 2762 by the Drug Enforcement Administration (DEA).[4]
Halazepam was invented by Schlesinger Walter in the U.S. It was marketed as an anti-anxiety agent in 1981. However, Halazepam is not commercially available in the United States because it was withdrawn by its manufacturer for poor sales.[5]