Pharmacokinetics of hydrorphone hydrochloride after intravenous and subcutaneous administration in ferrets (Mustela putorius furo)

Abstract

ObjectiveTo determine the pharmacokinetic profile of hydromorphone 0.2 mg kg–1 administered by the intravenous (IV) and subcutaneous (SC) route in ferrets. Study designRandomized, crossover study. AnimalsA group of eight adult ferrets weighting (mean ± standard deviation) 1.02 ± 0.22 kg. MethodsHydromorphone hydrochloride 0.2 mg kg–1 was administered IV or SC with a washout period of 7 days. Blood samples were collected from a jugular catheter before administration of hydromorphone and at 5, 10, 15, 20, 30, 45, 60, 90, 120, 240, 360, 480 and 720 minutes after hydromorphone administration. Plasma hydromorphone concentrations were determined by liquid chromatography/tandem mass spectrometry. Data were analyzed using a non-linear mixed effects model. ResultsThe hydromorphone effective half-life was (t1/2) 45 min–1. Systemic clearance (Cls) and the volume of distribution (Vdss) following IV administration were 84.8 mL kg–1 min–1 and 5.59 L kg–1, respectively. The maximum observed plasma concentration was 59.53 ± 14.02 ng mL–1 within 10 minutes following SC administration. The SC bioavailability was 102.0%. Conclusions and clinical relevanceAdministration of IV and SC hydromorphone (0.2 mg kg–1) was characterized by a high clearance, short terminal half-life and large volume of distribution. Hydromorphone plasma concentrations remained greater than 2 ng mL–1 for 2 hours in most ferrets, a threshold reported to provide antinociceptive effects in other species. Hydromorphone was well absorbed following SC injection, providing an alternative administration route for clinical use in ferrets.