Didesmethylsibutramine (Dinorsibutramine , Bisnorsibutramine, BTS-54524) is an active metabolite of the anorectic drug sibutramine that has been identified as an adulterant in weight loss supplements.[1][2] Data on the activity of didesmethylsibutramine in humans is limited, although a case of psychosis associated with didesmethylsibutramine use was reported in 2019.[3]
Didesmethylsibutramine acts as a triple reuptake inhibitor, blocking the reabsorption of serotonin, dopamine, and norepinephrine from neuronal synapses.[5] The (R)-enantiomer of didesmethylsibutramine is a more potent inhibitor of monoamine reuptake than the (S)-enantiomer and possesses significantly stronger anorectic activity in animals.[6]
Pharmacokinetics
Following sibutramine administration in humans, didesmethylsibutramine (M2) is formed through the n-demethylation of desmethylsibutramine (M1) by CYP2B6.[7] Elevated plasma levels of sibutramine are observed with concomitant use of CYP2B6 inhibitors (e.g. clopidogrel) and in individuals with certain CYP2B6 genotypes due to the reduced conversion of sibutramine into desmethylsibutramine.[8][9]
^Kim HJ, Lee JH, Park HJ, Cho SH, Cho S, Kim WS (4 May 2014). "Monitoring of 29 weight loss compounds in foods and dietary supplements by LC-MS/MS". Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment. 31 (5): 777–783. doi:10.1080/19440049.2014.888497. PMID24499058. S2CID31818942.
^Nisoli E, Carruba MO (October 2000). "An assessment of the safety and efficacy of sibutramine, an anti-obesity drug with a novel mechanism of action". Obesity Reviews. 1 (2): 127–139. doi:10.1046/j.1467-789x.2000.00020.x. PMID12119986. S2CID20553857.
^Glick SD, Haskew RE, Maisonneuve IM, Carlson JN, Jerussi TP (May 2000). "Enantioselective behavioral effects of sibutramine metabolites". European Journal of Pharmacology. 397 (1): 93–102. doi:10.1016/S0014-2999(00)00216-8. PMID10844103.
^Bae SK, Cao S, Seo KA, Kim H, Kim MJ, Shon JH, et al. (August 2008). "Cytochrome P450 2B6 catalyzes the formation of pharmacologically active sibutramine (N-{1-[1-(4-chlorophenyl)cyclobutyl]-3-methylbutyl}-N,N-dimethylamine) metabolites in human liver microsomes". Drug Metabolism and Disposition. 36 (8): 1679–1688. doi:10.1124/dmd.108.020727. PMID18474675. S2CID206495548.
^Bae JW, Jang CG, Lee SY (December 2011). "Effects of clopidogrel on the pharmacokinetics of sibutramine and its active metabolites". Journal of Clinical Pharmacology. 51 (12): 1704–1711. doi:10.1177/0091270010388651. PMID21209232. S2CID121878.
^Pan W, Bae SK, Shim EJ, Park SE, Lee SS, Park SJ, et al. (February 2013). "Effects of clopidogrel and clarithromycin on the disposition of sibutramine and its active metabolites M1 and M2 in relation to CYP2B6*6 polymorphism". Xenobiotica; the Fate of Foreign Compounds in Biological Systems. 43 (2): 211–218. doi:10.3109/00498254.2012.706722. PMID22830954. S2CID25985390.