The effect of the novel partial alpha2-adrenoceptor agonist naphthylmedetomidine on the basic cardiorespiratory parameters and behavior in rhesus monkeys.

BACKGROUND

The aim of this study was to compare cardiorespiratory and behavioral profile of a new alpha 2-adrenoceptor ligand naphthylmedetomidine with medetomidine in rhesus monkeys.

METHODS

Naphthylmedetomidine or medetomidine (50 microg/kg) together with ketamine (3 mg/kg) and hyaluronidase (150 IU/kg) i.m was administered to 35 rhesus monkeys. Behavioral changes were then observed together with blood pressure, heart rate and oxygen saturation of hemoglobin.

RESULTS

The onset of sedation, ataxia, and reduction of aggression was similar in both treatment groups. Immobilization was observed only in medetomidine treated animals, while in naphthylmedetomidine treated animals loss of aggressiveness was observed but the animals never completely lost mobility. Naphthylmedetomidine showed less prominent effects on cardiorespiratory functions compared with medetomidine.

CONCLUSIONS

Our results suggest that naphthylmedetomidine can be used to induce sedation in primates and other small animals while avoiding the serious side effects observed after administration of the currently used full alpha(2)-AR agonists.