Pharmacokinetic Profile of Fentanyl in the Koala () after Intravenous Administration, and Absorption via a Transdermal Patch.

Fentanyl was administered as a single intravenous bolus injection at 5 µg/kg to five koalas and fentanyl plasma concentrations for a minimum of 2 h were quantified by an enzyme-linked immunosorbent assay (ELISA). The median (range) fentanyl elimination half-life and clearance were 0.53 (0.