Use of pregabalin for the pre and post-operative management of cats undergoing ovariohysterectomy

Domestic cats frequently experience significant stress and anxiety during veterinary handling, transportation, and the perioperative period. While gabapentin (GBP) is widely used to alleviate these symptoms, pregabalin (PGB) offers a more potent alternative due to its higher affinity for the alpha 2-delta (α2-δ) subunit of voltage-dependent calcium channels (1). This binding modulates the release of excitatory neurotransmitters such as glutamate and substance P, providing both anxiolytic and analgesic effects(2). Despite its favorable pharmacokinetic profile characterized by high bioavailability (94%) and a long half-life in cats clinical data regarding its efficacy in postoperative pain management remain limited. This study aimed to evaluate the sedative and analgesic effects of a single oral dose of pregabalin (PGB) in cats undergoing ovariohysterectomy, and to assess its impact on physiological variables and pain scores. It was hypothesized that PGB, in addition to its sedative effect, would provide a good analgesic effect and could therefore be used to enhance the multimodal perioperative protocol. In this prospective, randomized, blinded clinical trial, 60 healthy female cats (ASA I) were enrolled. Cats were randomly assigned to either Group P (Pregabalin, n=30) or Group C (Control, n=30). Group P received 5 mg/kg of PGB orally 90 minutes before hospital admission, while Group C received empty capsules (placebo) identically. Sedation was assessed after premedication using a Feline Multiparametric Sedation Scale (FMSS) and a Simple Qualitative Scale (SQS). All cats were premedicated with methadone (0.2 mg/kg IM) and alfaxalone (1 mg/kg IM). Anesthesia was induced with propofol intravenously (IV) at a dose of 2 mg/kg and maintained with isoflurane. Physiological parameters (HR, RR, SpO2, EtCO2, Blood Pressure, and Temperature) were monitored throughout surgery. Postoperative pain was evaluated at 0, 15, 30, and 60 minutes after extubation using the Glasgow Feline Composite Measure Pain Scale (CMPS-Feline) and the Feline Grimace Scale (FGS) (3). Statistical analysis included Two-way ANOVA for physiological data and Wilcoxon-Mann-Whitney tests for pain and sedation scores (p < 0.05). There were no significant differences between groups regarding age, weight, or surgical and anesthesia duration. However, five cats from the control group were excluded due to the requirement of rescue analgesia during the procedure. Sedation scores were significantly higher in Group P compared to Group C (p < 0.001). Postoperatively, pain scores (CMPS-Feline and FGS) were significantly lower in the pregabalin-treated group at all time points (p < 0.001). No adverse effects, such as ataxia or vomiting, were observed in any subject. Results demonstrate that a single oral dose of 5 mg/kg of pregabalin provides effective preoperative sedation and sustained postoperative analgesia in cats. Furthermore, the significantly lower postoperative pain scores in Group P suggest a pre-emptive analgesic effect, likely mediated by the modulation of central sensitization and inhibitory effects on neurotransmitter release. In conclusion, pregabalin is a valuable and safe addition to multimodal anesthetic protocols for feline ovariohysterectomy, offering superior sedation and contributing to a more comfortable recovery compared to traditional protocols.