Cardiovascular effects of morphine during hypothermia
Alcaraz, C.; Bansinath, M.; Turndorf, H.; Puig, M.M.
Archives Internationales de Pharmacodynamie et de Therapie 297: 133-147
1989
ISSN/ISBN: 0003-9780 PMID: 2730232 Document Number: 340582
The cardiovascular effects of morphine were determined in anesthetized dogs at 37 and 30.degree. C. Intravenous (i.v., 1 mg/kg) but not intracisternal (i.c., 0.1 mg/kg) morphine produced a significant cardiovascular depression only at 30.degree. C. These effects were antagonized by i.v. naloxone (1 mg/kg) suggesting a peripherally mediated opiate mechanism. Moreover, hypothermia significantly increased plasma and cerebrospinal fluid morphine levels and enhanced the morphine-induced histamine release. The results suggest that opiates could have detrimental effects in patients with poor cardiovascular reserve in which high doses of opiates and hypothermia may be used concomitantly.