Clinical data
Routes of
Oral, Sublingual, rectal
Legal status
Legal status
Pharmacokinetic data
Elimination half-life17 hours
  • 8-Bromo-1-methyl-6-(pyridin-2-yl)-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepine
CAS Number
PubChem CID
Chemical and physical data
Molar mass354.211 g·mol−1
3D model (JSmol)
  • CC1=NN=C2CN=C(C3=NC=CC=C3)C3=CC(Br)=CC=C3N12
  • InChI=1S/C16H12BrN5/c1-10-20-21-15-9-19-16(13-4-2-3-7-18-13)12-8-11(17)5-6-14(12)22(10)15/h2-8H,9H2,1H3

Pyrazolam (SH-I-04)[2] is a benzodiazepine derivative originally developed by a team led by Leo Sternbach at Hoffman-La Roche in the 1970s.[3] It has since been "rediscovered" and sold as a designer drug since 2012.[4][5][6][7][8][9][excessive citations]

Pyrazolam has structural similarities to alprazolam[10] and bromazepam. Unlike other benzodiazepines, pyrazolam does not appear to undergo metabolism, instead being excreted unchanged in the urine.[4]

Legal status

United Kingdom

In the UK, pyrazolam has been classified as a Class C drug by section 5 of the May 2017 amendment to The Misuse of Drugs Act 1971 along with several other designer benzodiazepine drugs.[11]

See also


  1. ^ (customs (prohibited imports) regulations 1956 - schedule 4, 1956)
  2. ^ Clayton T, Poe MM, Rallapalli S, Biawat P, Savić MM, Rowlett JK, et al. (2015). "A Review of the Updated Pharmacophore for the Alpha 5 GABA(A) Benzodiazepine Receptor Model". International Journal of Medicinal Chemistry. 2015: 430248. doi:10.1155/2015/430248. PMC 4657098. PMID 26682068.
  3. ^ US 3954728, Sternbach LH, Walser A, "Preparation of triazolo benzodiazepines and novel compounds", issued 4 May 1976, assigned to Hoffmann La Roche Inc. 
  4. ^ a b Moosmann B, Hutter M, Huppertz LM, Ferlaino S, Redlingshöfer L, Auwärter V (July 2013). "Characterization of the designer benzodiazepine pyrazolam and its detectability in human serum and urine". Forensic Toxicology. 31 (2): 263–271. doi:10.1007/s11419-013-0187-4. S2CID 23273522.
  5. ^ Moosmann B, King LA, Auwärter V (June 2015). "Designer benzodiazepines: A new challenge". World Psychiatry. 14 (2): 248. doi:10.1002/wps.20236. PMC 4471986. PMID 26043347.
  6. ^ Pettersson Bergstrand M, Helander A, Hansson T, Beck O (April 2017). "Detectability of designer benzodiazepines in CEDIA, EMIT II Plus, HEIA, and KIMS II immunochemical screening assays". Drug Testing and Analysis. 9 (4): 640–645. doi:10.1002/dta.2003. PMID 27366870.
  7. ^ Høiseth G, Tuv SS, Karinen R (November 2016). "Blood concentrations of new designer benzodiazepines in forensic cases". Forensic Science International. 268: 35–38. doi:10.1016/j.forsciint.2016.09.006. PMID 27685473.
  8. ^ Manchester KR, Maskell PD, Waters L (March 2018). "Experimental versus theoretical log D7.4 , pKa and plasma protein binding values for benzodiazepines appearing as new psychoactive substances". Drug Testing and Analysis. 10 (8): 1258–1269. doi:10.1002/dta.2387. PMID 29582576.
  9. ^ Manchester KR, Waters L, Haider S, Maskell PD (July 2022). "The blood-to-plasma ratio and predicted GABAA-binding affinity of designer benzodiazepines". Forensic Toxicology. 40 (2): 349–356. doi:10.1007/s11419-022-00616-y. PMC 9715504. PMID 36454409. S2CID 247455284.
  10. ^ Hester JB, Rudzik AD, Kamdar BV (November 1971). "6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepines which have central nervous system depressant activity". Journal of Medicinal Chemistry. 14 (11): 1078–1081. doi:10.1021/jm00293a015. PMID 5165540.
  11. ^ "The Misuse of Drugs Act 1971 (Amendment) Order 2017".