Pharmacokinetics of a single, deep subcutaneous dose of buprenorphine hydrochloride in four-toed hedgehogs (Atelerix albiventris)

Abstract

Background

There is little information regarding analgesia in pet hedgehogs. A recent study demonstrated that a single subcutaneous (SC) injection of buprenorphine hydrochloride in four-toed hedgehogs produced antinociception up to 36 to 48 hours, longer than for any other species. The goal of this study was to evaluate the pharmacokinetics of a single, deep SC dose of buprenorphine hydrochloride in four-toed hedgehogs to expand our understanding of clinical pharmacokinetics in this popular pet species.

Methods

Baseline blood samples were collected from the jugular veins of 6 adult hedgehogs under isoflurane anesthesia. Buprenorphine (0.05 mg/kg) was administered into the dorsal spined skin overlying the scapula at an approximate depth of 1.3 cm. Subsequent blood samples were collected at 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 72, 96, 120 hours after buprenorphine administration. Heparinized blood samples were stored on ice then centrifuged and plasma removed within 4 hours of collection. Plasma was frozen at -80ºC until analysis. Plasma levels of buprenorphine were quantified using liquid chromatography-tandem mass spectrometry and a noncompartmental model was used to determine pharmacokinetic parameters.

Results

Median (range) maximum plasma concentration was 1.6 (0.7–8.0) ng/mL and the time to maximum plasma concentration was 4.3 (0.5–36) hr. The plasma terminal half-life was 25.3 (16.9–41.5) hr.

Conclusions and Clinical Relevance

Buprenorphine hydrochloride has a very long half-life and marked variability in plasma concentrations following deep SC administration into the mantle in hedgehogs. Further research is needed to determine a correlation between plasma buprenorphine levels and a clinical analgesic effect in this species.