Dioxaphetyl butyrate

Dioxaphetyl butyrate (INN; trade names Amidalgon, Spasmoxal) is an opioid analgesic which is a diphenylacetic acid derivative, related to other open-chain opioid drugs such as dextropropoxyphene, levacetylmethadol (LAAM), lefetamine and dimenoxadol.

It produces similar effects to other opioids, including dependence, euphoria, analgesia, sedation, constipation, dizziness and nausea.