Pharmacokinetics and Pharmacodynamics of Gabapentin in Horses: A Potentially Useful Analgesic Agent for the Treatment of Laminitis

Abstract

Gabapentin has been used to treat chronic pain in people and small animals. To date, no study has reported its use in horses for the treatment of chronic painful conditions. The clinical effectiveness of gabapentin as an analgesic in horses with chronic lameness was evaluated in a double-blinded crossover study. Six horses with chronic lameness referable to musculoskeletal pathology were randomly assigned to one of three treatments: 5 and 10 mg/kg body weight of gabapentin, and placebo administered PO three times daily for 14 days. All horses received each treatment separated by a 2-week interval. Complete blood count and serum biochemistry were performed before and after each treatment. Lameness was evaluated subjectively by blinded observers before, during, and after each treatment period. The data were analyzed using the general linear model for repeated-measures analysis of variance. A P value of < .05 was considered significant. No significant reduction in lameness level was observed while receiving either gabapentin dose when compared with the placebo group. Further studies are necessary to determine effective plasma concentration and length of treatment period after PO administered gabapentin for analgesia in horses with chronic lameness.