Antagonism of ketamine anesthesia in cats by 4-aminopyridine and yohimbine
Hatch, R.C.; Booth, N.H.; Kitzman, J.V.; Wallner, B.M.; Clark, J.D.
American Journal of Veterinary Research 44(3): 417-423
1983
ISSN/ISBN: 0002-9645 PMID: 6132571 Document Number: 219876
Two groups of fasted cats (8 cats/group) were injected i.m. with atropine (0.05 mg/kg body wt) plus an anesthetic dosage of ketamine (20 mg/kg) in weekly experiments. On loss of righting reflex, group 1 (control) cats were given an i.v. injection of saline solution. Group 2 cats were given an i.v. injection of a mixture of 4-aminopyridine (4-AP; 0.6 mg/kg) plus yohimbine (0.25 mg/kg, wk 1), 4-AP alone (0.6 mg/kg; wk 2), or yohimbine alone (0.25 mg/kg; wk 3). When the control cats regained the ability to walk, they were given an i.v. injection of the same test antagonist(s) as the principals were given, so that all cats had the same total drug experience each week. The combination of 4-AP + yohimbine appeared to be a safe and effective partial antagonist of ketamine anesthesia in cats, although ketamine catalepsy was not antagonized. The antagonist combination may prove useful for producing rapid arousal in cats given anesthetic dosages or overdoses of ketamine, or for arousal of animals anesthetized with ketamine in combination with other drugs.