Specific Substances: Oxazepam
Nomination Date: 03/10/1986
Rationale: Oxazepam is a metabolite of most benzodiazepines marketed. These drugs are among the most often prescribed in medicine and have been used primarily as antianxiety/hypnotics for many years. Most have some carcinogenicity studies, but none have complete two species bioassays similar to protocols currently followed by the NTP. Increased incidences of tumors in rats exposed to these drugs has been observed. However, it is not known whether the types of tumors observed are specific for each chemical or characteristic of certain benzodiazepine compounds.