Thebaine (paramorphine) is an opiate alkaloid. A minor constituent of opium, thebaine is chemically similar to both morphine and codeine, but has stimulatory rather than depressant effects, causing strychnine-like convulsions at higher doses. Thebaine is not used therapeutically, but can be converted industrially into a variety of compounds including oxycodone, oxymorphone, nalbuphine, naloxone, naltrexone, buprenorphine and etorphine. It is controlled in Schedule II of the Controlled Substances Act as well as under international law. Thebaine is listed as a Class A drug under the Misuse of Drugs Act 1971 in the United Kingdom.