Single- and multiple-dose pharmacokinetics of sotalol hydrochloride in healthy cats

Abstract

Introduction/objectivesThe objective of this study was to describe the single- and multiple-dose pharmacokinetics and urinary elimination of sotalol in healthy cats. AnimalsSix adult purpose-bred cats Materials and methodsCats were administered 2 mg sotalol/kg body weight as a single intravenous bolus and as a single oral dose in a randomized crossover study with a two-week washout period. The same cats then received 3 mg sotalol/kg orally every 12 h for two weeks. Blood samples were collected at predetermined time points for 48 h postdose for quantification of sotalol using ultra-high-pressure liquid chromatography with mass spectrometry. Non-compartmental analysis was used to obtain pharmacokinetic parameters. Data are presented as median (min–max). ResultsFollowing intravenous administration, plasma clearance and volume of distribution were 9.22 mL/min/kg (5.69–10.89 mL/min/kg) and 2175.56 mL/kg (1961–2341.57 mL/kg), respectively. Bioavailability was 88.41% (62.75–130.29) following a single oral dose. Peak plasma concentration (Cmax) and time to Cmax were 0.94 μg/mL (0.45–1.17 μg/mL) and 1.5 h (0.5–4 h) after a single oral dose (2 mg/kg), and 2.29 μg/mL (1.91–2.48 μg/mL) and 1.0 h (0.5–1.5 h) with chronic oral dosing (3 mg/kg), respectively. Elimination half-life was 2.75 h (2.52–4.10 h) and 4.29 h (3.33–5.53 h) for single and chronic oral dosing, respectively. Accumulation index was 1.17 (1.09–1.29) after chronic dosing. Urinary sotalol recovery was 81–108% of the intravenous dose. ConclusionsOral sotalol administration resulted in plasma concentrations reportedly efficacious in other species, with good to excellent oral bioavailability. Urinary excretion appears to be a major route of elimination. Following repeated oral dosing, minimal drug accumulation was estimated. Additional studies in cats are recommended due to the possibility of nonlinear kinetics.