Acetylmethadol

Acetylmethadol (INN), also known as methadyl acetate (USAN), is a synthetic opioid analgesic.^[2] It is a racemic mixture ofalphacetylmethadol (α-acetylmethadol) and betacetylmethadol (β-acetylmethadol), which are in turn racemic mixtures oflevacetylmethadol (LAAM; L-α-acetylmethadol) and D-α-acetylmethadol and L-β-acetylmethadol and D-β-acetylmethadol, respectively.^[2] Hence, acetylmethadol has four possible optical isomers.^[2] All of these isomers have been shown to partially or fully substitute for the discriminative stimulus effects of heroin in rats, and thus it can be inferred that, in addition to LAAM which is used clinically as such, they are all likely to be active opioid analgesics in humans.^[2]

In the United States, acetylmethadol and its individual isomers are all Schedule I drugs under the Controlled Substances Act, except LAAM, which is Schedule II and was used clinically until 1993. Acetylmethadol has an ACSCN of 9601. The isomers have individual ACSCNs, which are as follows: Alphacetylmethadol 9603, Betacetylmethadol 9607, LAAM 9648. All of the above have annual manufacturing quotas of 2 grammes as of 2013, except LAAM, which is 4 grammes.