Meclonazepam ((''S'')-3-methylclonazepam) is a

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

derivative similar in structure to

clonazepam Clonazepam, sold under the brand name Klonopin among others, is a benzodiazepine medication used to prevent and treat anxiety disorders, seizures, bipolar mania, agitation associated with psychosis, obsessive–compulsive disorder (OCD), and ...

. It was first discovered by a team at

Hoffmann-La Roche F. Hoffmann-La Roche AG, commonly known as Roche (), is a Swiss multinational holding healthcare company that operates worldwide under two divisions: Pharmaceuticals and Diagnostics. Its holding company, Roche Holding AG, has shares listed on ...

in the 1970s. It has

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

and

anxiolytic An anxiolytic (; also antipanic or anti-anxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...

actions like those of other benzodiazepines, and also has anti-parasitic effects against the parasitic worm ''

Schistosoma mansoni A paired couple of ''Schistosoma mansoni''. ''Schistosoma mansoni'' is a water-borne parasite of humans, and belongs to the group of blood flukes (''Schistosoma''). The adult lives in the blood vessels ( mesenteric veins) near the human inte ...

''. Meclonazepam was never used as medicine and instead appeared online as a

designer drug A designer drug is a structural or functional analog of a controlled substance that has been designed to mimic the pharmacological effects of the original drug, while avoiding classification as illegal and/or detection in standard drug tests. ...

Pharmacology

Its sedative and anxiolytic abilities are attributed to the same mechanism used by other benzodiazepine drugs: modulation of the GABA_A receptor in the brain. This psychoactive activity makes it useful for recreational use. The sedating side effect would also make it unsuitable for routine use as an antiparasitical. Schistosomal parasites do not have an ortholog of the GABA_A receptor. Instead, meclonazepam seems to cause a rapid calcium influx, leading to muscle contraction and tegument damage. In 2023, meclonazepam is shown to activate a calcium-permeable schistosome TRP (transient receptor potential), making this TRP a very likely candidate for its parasite receptor. Some work has been done to produce two meclonazepam derivatives that show less sedation and more anti-parasite activity in mice. They seem to do this by crossing the blood-brain barrier less readily.

Legal Issues

United Kingdom

In the UK, meclonazepam has been classified as a

Class C drug The Misuse of Drugs Act 1971 (c. 38) is an act of the Parliament of the United Kingdom. It represents action in line with treaty commitments under the Single Convention on Narcotic Drugs, the Convention on Psychotropic Substances, and the Uni ...

by the May 2017 amendment to The Misuse of Drugs Act 1971 along with several other designer benzodiazepine drugs.

Pharmacology

Legal Issues

United Kingdom

See also

References

Further reading