Diethylthiambutene (Thiambutene, Themalon, Diethibutin, N,N-Diethyl-1-methyl-3,3-di-2-thienylallylamine) is an opioidanalgesic drug developed in the 1950s which was mainly used as an anesthetic in veterinary medicine and continues, along with the other two thiambutenes dimethylthiambutene and ethylmethylthiambutene to be used for this purpose, particularly in Japan. It is now under international control under Schedule I of the UN Single Convention On Narcotic Drugs 1961, presumably due to high abuse potential, although little more information is available. It is listed under Schedule I of the US Controlled Substances Act as a Narcotic and has an ACSCN of 9616 with zero annual manufacturing quota as of 2013.
^BECKETT AH, CASY AF, HARPER NJ, PHILLIPS PM. Analgesics and their antagonists: some steric and chemical considerations. II. The influence of the basic group on physico-chemical properties and the activity of methadone and thiambutene-type compounds. Journal of Pharmacy and Pharmacology. 1956 Nov;8(11):860-73.
^Hayes MJ. The use of thiambutene hydrochloride. The Veterinary Record. 1968 Nov 16;83(20):528.
^Harbison WD, Slocombe RF, Watts SJ, Stewart GA. Thiambutene and acepromazine as analgesic and preanaesthetic agents in horses and sheep. Australian Veterinary Journal. 1974 Dec;50(12):543-6.