Pharmacokinetics of gamma-hydroxybutyric acid in 6-week-old swine (Sus scrofa domesticus) after intravenous and oral administration

Sedative as well as protective effects during hypoxia have been described for gamma-hydroxybutyric acid (GHB). Six swine (Sus scrofa domesticus) of 6 weeks old were administered NaGHB at a dose of 500 mg/kg intravenously (IV) and 500 and 750 mg/kg orally (PO) in a triple cross-over design. Repeated blood sampling was performed to allow pharmacokinetic analysis of GHB. Whole blood concentration at time point 0 after IV administration was 1727.21 +/- 280.73 mu g/mL, with a volume of distribution of 339.45 +/- 51.41 mL/kg and clearance of 164.94 +/- 47.05 mL/(kg h). The mean peak plasma concentrations after PO administration were 326.57 +/- 36.70 and 488.01 +/- 154.62 mu g/mL for 500 mg/kg and 750 mg/kg, respectively. These were recorded at 1.42 +/- 0.72 and 1.58 +/- 0.58 h after PO dose for GHB 500 mg/kg and 750 mg/kg, respectively. The elimination half-life for IV and PO 500 mg/kg and PO 750 mg/kg dose was respectively 1.33 +/- 0.30, 1.16 +/- 0.31 and 1.11 +/- 0.33 h. The bioavailability (F) for PO administration was 45%. No clinical adverse effects were observed after PO administration. Deep sleep was seen in one animal after IV administration, other animals showed head pressing and ataxia.

Automated summary

Sedative and protective effects of gamma-hydroxybutyric acid (GHB) during hypoxia were investigated in this study. Six-week-old pigs were administered NaGHB intravenously and orally, and the pharmacokinetics of GHB were analyzed. The bioavailability of GHB after oral administration was 45%, and no adverse effects were observed. However, deep sleep and abnormal behavior were observed after intravenous administration.