Betameprodine is an opioid analgesic classified by the United States Drug Enforcement Administration under Schedule I of illegal substances. The stereoisomer alphameprodine is similarly classified, and was more widely used. Betameprodine is a structural analogue of meperidine. It exerts physiological effects characteristic of opioids, such as analgesia, euphoria and sedation -- as well as itching, nausea, and respiratory depression. (en)