Pharmacological study of Mequitazine (LM-209) . (V) . Pharmacological actions of a main metabolite of LM-209, mequitazine sulfoxide (LM-209 SO)
Hojo, M.; Nagasaka, Y.; Katayama, O.; Serizawa, I.
Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica 78(5): 431-438
1981
ISSN/ISBN: 0015-5691 PMID: 6120129 Document Number: 171973
The pharmacological action of a main metabolite of mequitazine (LM-209), mequitazine sulfoxide (LM-209 SO), was compared with data on LM-209 to investigate whether LM-209 is metabolized in vivo to the active form and if it has pharmacological actions. In the excised ileum of guinea pigs, the antihistaminic and anticholinergic activities of LM-209 SO were .apprx. 1/8 and 1/20, respectively, of LM-209. The protective activity of LM-209 SO on sudden death induced by histamine in mice was .apprx. 1/2.5 of LM-209. Acute toxicity of LM-209 SO given orally to mice was 1/3 of LM-209. In the EEG of rabbits, LM-209 SO did not affect the spontaneous pattern or the arousal and recruiting responses. The mydriatic and local anesthetic activities of LM-209 SO were significantly less than those of LM-209. The pharmacological activities and toxicity of LM-209 SO were significantly less potent than those of LM-209.