Cyproheptadine-d3 is intended for use as an internal standard for the quantification of cyproheptadine by GC- or LC-MS. Cyproheptadine is an antihistamine with antiserotonergic and anticholinergic activities.1 It binds to histamine H1, muscarinic, and serotonin 5-HT2 receptors (Kis = 0.38, 1.26, and 0.83 nM, respectively, in radioligand binding assays).2 Cyproheptadine reduces histamine-induced spasms in isolated guinea pig ileum (IC75 = 0.0014 μg/ml).3 It protects against intravenous histamine diphosphate-induced death with a 50% protective dose (PD50) value of 0.08 mg/kg and delays induction of aerosolized histamine diphosphate-induced coughing (ED100sec = 0.29 mg/kg) in guinea pigs. Cyproheptadine also inhibits the lysine methyltransferase SET7/9 (IC50 = 1 μM), decreasing the expression of estrogen receptor α (ERα) in MCF-7 cells.4 Formulations containing cyproheptadine have been used in the treatment of allergic reactions including rhinitis, conjunctivitis, and urticaria.
|1. Greaves, M.W. Antihistamines. Dermatol. Clin. 19(1), 53-62 (2001).|2. Kakiuchi, M., Ohashi, T., Musoh, K., et al. Studies on the novel antiallergic agent HSR-609: Its penetration into the central nervous system in mice and guinea pigs and its selectivity for the histamine H1-receptor. Jpn. J. Pharmacol. 73(4), 291-298 (1997).|3. Lish, P.M., Robbins, S.I., and Peters, E.L. Specificity of antihistamine drugs and involvement of the adrenergic system in histamine deaths in the guinea pig. J. Pharmacol. Exp. Ther. 153(3), 538-543 (1966).|4. Takemoto, Y., Ito, A., Niwa, H., et al. Identification of cyproheptadine as an inhibitor of SET domain containing lysine methyltransferase 7/9 (Set7/9) that regulates estrogen-dependent transcription. J. Med. Chem. 59(8), 3650-3660 (2016).