title: Reduction in sympathetic nerve activity as a possible mechanism for the hypothermic effect of oseltamivir, an anti-influenza virus drug, in normal mice.
abstract: Oseltamivir, an anti-influenza virus drug, has strong antipyretic effects in mice (Biological and Pharmaceutical Bulletin, 31, 2008, 638) and patients with influenza. In addition, hypothermia has been reported as an adverse event. The prodrug oseltamivir is converted to oseltamivir carboxylate (OC), an active metabolite of influenza virus neuraminidase. In this study, core body temperature was measured in mice, and oseltamivir and OC were administered intracerebroventricularly (i.c.v.) or intraperitoneally (i.p). Low i.c.v. doses of oseltamivir and OC dose-dependently produced hypothermia. Zanamivir (i.c.v.), another neuraminidase inhibitor, did not produce hypothermia. These results suggested that the hypothermic effects of oseltamivir (i.p. and i.c.v.) and OC (i.c.v.) are not due to neuraminidase inhibition. OC (i.p.) did not lower body temperature. Although mecamylamine (i.c.v.) blocked the hypothermic effect of nicotine-administered i.c.v., the hypothermic effects of oseltamivir and OC (i.c.v.) were not blocked by mecamylamine (i.c.v.). The effect of oseltamivir (i.p.) was markedly increased by s.c.-pre-administered mecamylamine and also hexamethonium, a peripherally acting ganglionic blocker, suggesting their potentiating interaction at peripheral sites. The hypothermic effect of nicotine (i.c.v.) was decreased by lower doses of oseltamivir (i.c.v.), suggesting the anti-nicotinic action of oseltamivir. These results suggest that oseltamivir (i.p.) causes hypothermia through depression of sympathetic temperature regulatory mechanisms via inhibition of nicotinic receptor function and through unknown central mechanisms.
authors: Laboratory of CNS Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan. hiono@phar.nagoya-cu.ac.jp
authors: Hideki
authors: H
authors: Ono
authors: Yui
authors: Y
authors: Iwajima
authors: Yuko
authors: Y
authors: Nagano
authors: Kaori
authors: K
authors: Chazono
authors: Yasuhiro
authors: Y
authors: Maeda
authors: Masahiro
authors: M
authors: Ohsawa
authors: Shohei
authors: S
authors: Yamamoto
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D001831:Body Temperature; D018738:Hexamethonium / Q000494:pharmacology; D007035:Hypothermia / Q000139:chemically induced*; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D051379:Mice; D009439:Neuraminidase / Q000037:antagonists & inhibitors; D009538:Nicotine / Q000494:pharmacology; D053139:Oseltamivir / Q000031:analogs & derivatives* / Q000494:pharmacology*; D053243:Zanamivir / Q000494:pharmacology
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir; D018738:Hexamethonium; D008464:Mecamylamine; D009538:Nicotine; D009439:Neuraminidase; C535162:oseltamivir carboxylate; D053243:Zanamivir