美喹他嗪(mequitazine)由法国Aventis公司研发，商品名为Primalan，于1976年在法国上市，目前已在20多个国家销售。美喹他嗪为选择性H1受体拮抗剂，是无中枢镇静和抗胆碱能作用的长效抗组胺药，对外周H1受体有选择性拮抗作用，能抑制肥大细胞脱颗粒，调节迷走神经紧张性，从而阻止慢性过敏症状的发展。本品尚有轻度抗胆碱能作用。临床用于常年性及季节性过敏性皮炎、急慢性荨麻疹、过敏性结膜炎、虫咬性水肿、哮喘、各种皮肤瘙痒、湿疹等。
美喹他嗪口服吸收快，6h达峰值，t1/2为18h。口服后38h从体内清除，不易通过血-脑脊液屏障。体内分布广，血管渗透性高。肝内代谢，经胆汁排出体外。
甲喹吩嗪不能与单胺氧化酶抑制剂同用。与中枢抑制药(如中枢镇静药和镇静药)合用，可使中枢抑制作用加强。
Mequitazine is a potent H 1 -receptors selective antihistaminic drug widely studied and used for allergic disorders such as hay fever and urticaria. Mequitazine demonstrates significant bactericidal effects against all the tested clinical isolates including Ps. aeruginosa . Its effect against the Gram-positive isolates is more pronounced.
Mequitazine and clemizole antagonize the effect of histamine in guinea-pig ileum competitively. Mequitazine at 10 7 produces a parallel shift of the dose-response curve to acetylcholine in the rat duodenum. Mequitazine at highest concentration shows anticholinergic activity. Mequitazine inhibits contractile responses to KCl, phenylephrine (PE), 5-hydroxytryptamine (5-HT), and Ca 2+ in rat aorta.