3-Methylthiofentanyl

Year(s) and type of review / ECDD meetings
Drug Class

Recommendation (from TRS)

Substance identification
3-Methylthiofentanyl’ (CAS 86052-04-2), chemically § N-[3-methyl-1-[2-(2-thienyl)ethyl]-4-piperidyl]-propionanilide, is also known as NIH 10546 and MCV 4591. There are two chiral carbon atoms in the molecule so that four stereoisomers and two racemates are possible.

Similarity to known substances and effects on the CNS
The pharmacological profile of only one of the two racemates of 3-methylthiofentanyl ((+)-cis-3-methylthiofentany/) has been examined. This racemate behaves as a relatively selective mu-type opioid-receptor agonist. In rodent analgesic tests the substance is about 1000 times more potent than morphine.

Dependence potential
3-Methylthiofentanyl substitutes completely for morphine in morphine-dependent withdrawn monkeys and is about 1000 times more potent than morphine in this regard. No human studies are available concerning the dependence potential of 3-methylthiofentanyl.

Actual abuse and or/evidence of likelihood of abuse
3-Methylthiofentany/ is one of the fentanyl analogues that have appeared in the illicit drug traffic since late 1979. It has been identified in drug seizures in the USA by a Drug Enforcement Administration laboratory, and clandestine production has been demonstrated.

Therapeutic usefulness
At present, 3-methylthiofentanyl has no known therapeutic use.

Recommendation
The Committee found that there was sufficient evidence to indicate that 3-methylthiofentany! is liable to similar abuse to, and produces ill-effects similar to those seen with, drugs in Schedule I of the Single Convention on Narcotic Drugs, 1961, and that Convention as amended by the 1972 protocol. The Committee rated the abuse liability of the substance as high. The public health and social problems associated with the substance are extremely serious and there is no known therapeutic use. Therefore, the Committee recommended that 3-methylthiofentany! be controlled in Schedules J and IV of the Single Convention on Narcotic Drugs, 1961, and that Convention as amended by the 1972 protocol.

ECDD Recommendation

Inclusion in Schedule I and Schedule IV of the 1961 Convention on Narcotic Drugs