Pharmacokinetics of Gabapentin after Single, Oral Administration in Domestic Rabbits (oryctolagus Cuniculus)

Background: Gabapentin is used to treat seizures, neuropathic pain, and anxiety. Currently, dosage recommenda-tions for rabbits are extrapolated from other species. The objective of this study was to determine the pharmacoki-netics of gabapentin after single, oral administration in domestic rabbits.Methods: A randomized, crossover study was performed in male (n = 3) and female (n = 3) rabbits after adminis-tration of either 25 or 50 mg/kg gabapentin orally. Plasma concentrations of gabapentin were measured at 0, 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 4, 8, 12, 24, and 48 hours post-administration via liquid chromatography.Results: Mean maximum plasma concentrations were 17.70 and 16.83 mu g/mL for the 25 and 50 mg/kg doses, respectively. Mean times to maximum plasma concentration were 1.75 and 1.5 hours, and mean terminal half-lives were 10.2 and 9.44 hours for the 25 and 50 mg/kg doses, respectively. No adverse effects observed at either dose.Conclusions and clinical relevance: A single oral dose of gabapentin at 50 mg/kg did not result in higher plasma con-centrations compared to the 25 mg/kg dose and no differences were observed between males and females for either dosing group (P > 0.9).