This short advice letter is from the ACMD to the UK Home Secretary giving advice on O-desmethyltramadol.

O-desmethyltramadol (2-((dimethylamino)methyl)-1-(3-hydroxyphenyl)cyclohexanol) is the major metabolite of tramadol ((±)-trans-2-((dimethylamino)methyl)-1-(3-methoxyphenyl)cyclohexanol) and is a significantly more potent opiate than its parent drug.

The compound came to light as a material of concern during the ACMD‟s review of tramadol. The ACMD has sufficient concerns about the harmful properties of O-desmethyltramadol to submit advice separately and in advance of that on tramadol (scheduled for December 2012) so that early Ministerial consideration of the metabolite can be made.

O-desmethyltramadol is being offered for sale as a „legal high‟ and has been identified as an undeclared ingredient of a „legal high‟ product called „Krypton‟. „Krypton‟ is sold as an herbal material, claimed to consist of Kratom leaves (Mitragyna speciosa) from a Southeast Asian tree which, when chewed, produce narcotic and opiate-like effects. The packaging of „Krypton‟ is very similar to that of „Spice‟ (an herbal material containing synthetic cannabinoids), that is, brightly printed foil sachets containing a few grams of ground herbal material of unknown origin and authenticity. As with „Spice‟, the apparently natural herbal product has been found to be „spiked‟, in this case with synthetic O-desmethyltramadol, to produce additional psychoactive effects1.