Thermoregulatory, motor, behavioural, and nociceptive responses of rats to 3 long-acting neuroleptics.
We investigated physiological effects of intramuscular injections of the following 3 long-acting neuroleptics commonly used in wildlife management: haloperidol (0.05, 0.1, and 0.5 mg/kg body mass), zuclopenthixol acetate (0.5, 1, and 5 mg/kg), and perphenazine enanthate (1, 3, and 10 mg/kg), in a rat model. Body temperature and cage activity were measured by intra-abdominal telemeters. Nociceptive responses were assessed by challenges to noxious heat and pressure. Haloperidol (0.5 mg/kg) produced a significant nocturnal hypothermia (p < 0.05) and decreased nighttime cage activity and food intake. Zuclopenthixol (5 mg/kg) significantly decreased nighttime body temperature and cage activity and, at 1 mg/kg and 5 mg/kg, significantly decreased food intake 5-17 h after injection (p < 0.05). Perphenazine (10 mg/kg) significantly decreased nighttime body temperature and cage activity and, at all doses, significantly decreased food intake 5-17 h after injection (p < 0.05). Significant analgesic activity was evident in rats given 5 mg/kg zuclopenthixol up to 40 h after injection, and 10 mg/kg perphenazine from 48 to 96 h after injection (p < 0.0001). Zuclopenthixol (5 mg/kg) and perphenazine (10 mg/kg) had significant antihyperalgesic activities at 16 h postinjection and 24-48 h postinjection, respectively (p < 0.0001). Haloperidol had no significant antinociceptive activity at doses tested. Motor function was impaired in rats given 0.5 mg/kg haloperidol, 5 mg/kg zuclopenthixol and 10 mg/kg perphenazine. Effects of long-acting neuroleptics on body temperature, feeding, and activity were short-lasted and should not preclude their use in wildlife. Antinociceptive actions were longer-lasting, but were nonspecific, and we recommend additional analgesics for painful procedures during wildlife management.
Fick
L G
LG
Brain Function Research Unit, School of Physiology, University of Witwatersrand Medical School, Parktown, South Africa. fickgl@physiology.wits.ac.za
Fuller
A
A
Mitchell
D
D
D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects*; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D023421:Models, Animal; D009043:Motor Activity / Q000187:drug effects*; D010147:Pain Measurement; D051381:Rats; D017207:Rats, Sprague-Dawley; D019155:Veterinary Drugs / Q000008:administration & dosage / Q000494:pharmacology*
D000700:Analgesics; D014150:Antipsychotic Agents; D003692:Delayed-Action Preparations; D019155:Veterinary Drugs