Efficacy of Preemptive Analgesia with Amantadine for Controlling Postoperative Pain in Cats Undergoing Ovariohysterectomy

Simple Summary Amantadine, a drug initially used as an antiviral agent to treat the influenza A virus (though currently, its main application is in the treatment of Parkinson's disease) has also been used to control pain due to its mechanism of action: exerting non-competitive antagonism N-methyl-D-aspartate (NMDA) glutamatergic receptors, which participate in the neurophysiological project of pain via the inhibition of central sensitization. We hope that our study makes a significant contribution to the literature because the preemptive oral administration of amantadine at a dose of 5 mg/kg resulted in superior postsurgical pain control. In addition, the administration of amantadine did not result in cardiovascular or respiratory alterations or adverse effects during the intraoperative period of OVH in the evaluated cats.Abstract This study aimed to evaluate the effect of the preemptive administration of amantadine on postoperative analgesia in cats undergoing ovariohysterectomy and its influence on the physiological parameters. Twenty healthy domestic cats scheduled to undergo ovariohysterectomy at the Santa Cruz State University, Ilheus, were divided into two groups: the control group (Group C; n = 10) and the amantadine group (Group A; n = 10). The cats in Group C received placebo capsules 30 min prior to the standard anesthetic protocol, whereas those in Group A received 5 mg/kg of amantadine orally 30 min prior to the standard anesthetic protocol. Postoperative pain was assessed using the visual analog scale and the UNESP-Botucatu multidimensional scale for the evaluation of postoperative pain in cats. The administration of amantadine had no effect on the physiological parameters evaluated. The pain scores in Group A were lower than those in Group C, indicating that the frequency of rescue analgesic administration cats in Group A was lower. That way, preemptive oral administration of amantadine at a dose of 5 mg/kg was effective at controlling postoperative pain in cats undergoing ovariohysterectomy. Moreover, no adverse effects or alterations in the physiological patterns were observed in the treated animals.