Meclonazepam Explained

Meclonazepam^[1] ((S)-3-methylclonazepam) was discovered by a team at Hoffmann-La Roche in the 1970s and is a drug which is a benzodiazepine derivative similar in structure to clonazepam.^[2] It has sedative and anxiolytic actions like those of other benzodiazepines,^[3] and also has anti-parasitic effects against the parasitic worm Schistosoma mansoni.^[4]

Meclonazepam was never used as medicine and instead appeared online as a designer drug.^{[5] [6] [7] [8]}

Legal Issues

United Kingdom

In the UK, meclonazepam has been classified as a Class C drug by the May 2017 amendment to The Misuse of Drugs Act 1971 along with several other designer benzodiazepine drugs.^[9]

See also

• 3-Hydroxyphenazepam
• Desmethylflunitrazepam
• Nifoxipam
• Oxazepam
• Phenazepam
• Ro05-4082
• SH-I-048A

Further reading

• Abdul-Ghani RA, Loutfy N, Hassan A . Experimentally promising antischistosomal drugs: a review of some drug candidates not reaching the clinical use . Parasitology Research . 105 . 4 . 899–906 . October 2009 . 19588166 . 10.1007/s00436-009-1546-2 . 24122988 .

Notes and References

1. US . 4031078 . Benzodiazepine derivatives . Hoffmann La Roche Inc. . Szente A . 21 June 1977 .
2. Web site: The Lundbeck Institute . Meclonazepam . Psychotropics . Lundbeck .
3. Ansseau M, Doumont A, Thiry D, von Frenckell R, Collard J . Initial study of methylclonazepam in generalized anxiety disorder. Evidence for greater power in the cross-over design . Psychopharmacology . 87 . 2 . 130–135 . 1985 . 3931136 . 10.1007/bf00431795 . 9776700 .
4. O'Boyle C, Lambe R, Darragh A . Central effects in man of the novel schistosomicidal benzodiazepine meclonazepam . European Journal of Clinical Pharmacology . 29 . 1 . 105–108 . 1985 . 4054198 . 10.1007/bf00547377 . 1150292 .
5. Meyer MR, Bergstrand MP, Helander A, Beck O . Identification of main human urinary metabolites of the designer nitrobenzodiazepines clonazolam, meclonazepam, and nifoxipam by nano-liquid chromatography-high-resolution mass spectrometry for drug testing purposes . Analytical and Bioanalytical Chemistry . 408 . 13 . 3571–3591 . May 2016 . 27071765 . 10.1007/s00216-016-9439-6 . 25831532 .
6. Pettersson Bergstrand M, Helander A, Hansson T, Beck O . Detectability of designer benzodiazepines in CEDIA, EMIT II Plus, HEIA, and KIMS II immunochemical screening assays . Drug Testing and Analysis . 9 . 4 . 640–645 . April 2017 . 27366870 . 10.1002/dta.2003 .
7. Manchester KR, Maskell PD, Waters L . Experimental versus theoretical log D_7.4, pK_a and plasma protein binding values for benzodiazepines appearing as new psychoactive substances . Drug Testing and Analysis . 10 . 8 . 1258–1269 . March 2018 . 29582576 . 10.1002/dta.2387 .
8. Manchester KR, Waters L, Haider S, Maskell PD . The blood-to-plasma ratio and predicted GABA_A-binding affinity of designer benzodiazepines . Forensic Toxicology . 40 . 2 . 349–356 . July 2022 . 36454409 . 9715504 . 10.1007/s11419-022-00616-y .
9. Web site: The Misuse of Drugs Act 1971 (Amendment) Order 2017.