Propoxyphene is a drug often prescribed to treat pain and is related structurally to methadone. Propoxyphene is generally taken orally and its effects peak in 1 – 2 hours. Overdose of propoxyphene effects the brain and can cause severe euphoria. Extended use of propoxyphene can cause respiratory depression, analgesia, stupor, and coma.
Propoxyphene was withdrawn from the U.S. market in November 2010.