Mequitazine-d₈ hydrobromide  (Synonyms: LM-209-d₈ hydrobromide)

Mequitazine-d₈ hydrobromide is deuterated labeled Mequitazine (HY-B2168). Mequitazine is a potent, and long-acting histamine H₁ antagonist.

Stable heavy isotopes of hydrogen, carbon, and other elements have been incorporated into drug molecules, largely as tracers for quantitation during the drug development process. Deuteration has gained attention because of its potential to affect the pharmacokinetic and metabolic profiles of drugs^[1].
Mequitazine is a potent H₁-receptors selective antihistaminic drug widely studied and used for allergic disorders such as hay fever and urticaria^[2]. Mequitazine demonstrates significant bactericidal effects against all the tested clinical isolates including Ps. aeruginosa. Its effect against the Gram-positive isolates is more pronounced^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Mequitazine and clemizole antagonize the effect of histamine in guinea-pig ileum competitively. Mequitazine at 10⁷ produces a parallel shift of the dose-response curve to acetylcholine in the rat duodenum. Mequitazine at highest concentration shows anticholinergic activity^[4]. Mequitazine inhibits contractile responses to KCl, phenylephrine (PE), 5-hydroxytryptamine (5-HT), and Ca²⁺ in rat aorta^[5].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

411.43

C₂₀H₁₅D₈BrN₂S

[2H]C1=C([2H])C([2H])=C2SC3=C(C([2H])=C([2H])C([2H])=C3[2H])N(CC4CN5CCC4CC5)C2=C1[2H].Br

Room temperature in continental US; may vary elsewhere.

Please store the product under the recommended conditions in the Certificate of Analysis.

• [1]. Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019 Feb;53(2):211-216.  [Content Brief]

  [2]. Gonnot V, et al. Expedient synthesis of mequitazine an antihistaminic drug by palladium catalyzed allylic alkylation of sodium phenothiazinate. Chem Pharm Bull (Tokyo). 2009 Nov;57(11):1300-2.  [Content Brief]

  [3]. El-Nakeeb MA, et a. In vitro antibacterial activity of some antihistaminics belonging to different groups against multi-drug resistant clinical isolates. Braz J Microbiol. 2011 Jul;42(3):980-91.  [Content Brief]

  [4]. Martinez-Mir I, et al. Antihistaminic and anticholinergic activities of mequitazine in comparison with clemizole. J Pharm Pharmacol. 1988 Sep;40(9):655-6.  [Content Brief]

  [5]. Satake N, et al. Possible mechanisms of vasoinhibitory effects of mequitazine, an antiallergic agent, on the contractions of isolated rat aorta induced by K+, phenylephrine, 5-hydroxytryptamine, and Ca2+. J Cardiovasc Pharmacol. 1994 Apr;23(4):669-73.  [Content Brief]