Pharmacokinetics of oral gabapentin in greyhound dogs

The purpose of this study was to assess the pharmacokinetics of gabapentin in healthy greyhound dogs after single oral doses targeted at 10 and 20mg/kg PO. Six healthy greyhounds were enrolled (3 males, 3 females). Blood was obtained at predetermined times for the measurement of gabapentin plasma concentrations by liquid chromatography/mass spectrometry. Pharmacokinetic parameters were determined with computer software. The actual mean (and range) doses administered were 10.2 (9.1-12.0) mg/kg and 20.5 (18.2-24) mg/kg for the 10mg/kg and 20mg/kg targeted dose groups. The mean C(MAX) for the 10 and 20mg/kg groups were 8.54 and 13.22 microg/mL at 1.3 and 1.5h, and the terminal half-lives were 3.3 and 3.4h, respectively. The relative bioavailability of the 10mg/kg group was 1.13 compared to the 20mg/kg group. Gabapentin was rapidly absorbed and eliminated in dogs, indicating that frequent dosing is needed to maintain minimum targeted plasma concentrations.