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Molar mass299.261 g·mol−1
3D model (JSmol)

Desmethylflunitrazepam (also known as norflunitrazepam, Ro05-4435 and fonazepam) is a benzodiazepine that is a metabolite of flunitrazepam[1][2][3] and has been sold online as a designer drug.[4][5] It has an IC50 value of 1.499 nM for the GABAA receptor.[6][7]

See also


  1. ^ Busker, Ruud W.; van Henegouwen, Gerard M. J. Beijersbergen; Kwee, Brigitta M. C.; Winkens, Jos H. M. (May 1987). "Photobinding of flunitrazepam and its major photo-decomposition product N-desmethylflunitrazepam". International Journal of Pharmaceutics. 36 (2–3): 113–120. doi:10.1016/0378-5173(87)90145-1.
  2. ^ Coller, Janet K; Somogyi, Andrew A; Bochner, Felix (20 November 1998). "Quantification of flunitrazepam's oxidative metabolites, 3-hydroxyflunitrazepam and desmethylflunitrazepam, in hepatic microsomal incubations by high-performance liquid chromatography". Journal of Chromatography B. 719 (1–2): 87–92. doi:10.1016/S0378-4347(98)00383-1. PMID 9869368.
  3. ^ Kilicarslan, Tansel; Haining, Robert L.; Rettie, Allan E.; Busto, Usanda; Tyndale, Rachel F.; Sellers, Edward M. (1 April 2001). "Flunitrazepam Metabolism by Cytochrome P450s 2C19 and 3A4". Drug Metabolism and Disposition. 29 (4): 460–465. ISSN 1521-009X. PMID 11259331 – via
  4. ^ Moosmann, Bjoern; Bisel, Philippe; Franz, Florian; Huppertz, Laura M.; Auwärter, Volker (2016). "Characterization and in vitro phase I microsomal metabolism of designer benzodiazepines – an update comprising adinazolam, cloniprazepam, fonazepam, 3-hydroxyphenazepam, metizolam, and nitrazolam". Journal of Mass Spectrometry. 51 (11): 1080–1089. doi:10.1002/jms.3840. ISSN 1096-9888. PMID 27535017.
  5. ^ Katselou, Maria; Papoutsis, Ioannis; Nikolaou, Panagiota; Spiliopoulou, Chara; Athanaselis, Sotiris (2016). "Metabolites replace the parent drug in the drug arena. The cases of fonazepam and nifoxipam". Forensic Toxicology. 35 (1): 1–10. doi:10.1007/s11419-016-0338-5. ISSN 1860-8973. PMC 5214877. PMID 28127407.
  6. ^ Maddalena, Desmond J.; Johnston, Graham A. R. (February 1995). "Prediction of Receptor Properties and Binding Affinity of Ligands to Benzodiazepine/GABAA Receptors Using Artificial Neural Networks". Journal of Medicinal Chemistry. 38 (4): 715–724. doi:10.1021/jm00004a017. PMID 7861419.
  7. ^ So, Sung-Sau; Karplus, Martin (20 December 1996). "Genetic Neural Networks for Quantitative Structure−Activity Relationships: Improvements and Application of Benzodiazepine Affinity for Benzodiazepine/GABAA Receptors". Journal of Medicinal Chemistry. 39 (26): 5246–5256. doi:10.1021/jm960536o. PMID 8978853.