Pharmacokinetics of single-dose oral atorvastatin and its metabolites support therapeutic use in orange- winged Amazon parrots (Amazona amazonica)

OBJECTIVETo evaluate the plasma concentrations and determine pharmacokinetic parameters of atorvastatin and its primary active metabolites (para-and ortho-hydroxyatorvastatin) after administration of a single oral dose in orange-winged Amazon parrots (Amazona amazonica).ANIMALS8 adult orange-winged Amazon parrots (4 male, 4 female) of varying ages.METHODSA compounded oral suspension of atorvastatin 10 mg/mL was administered via oral gavage at 20 mg/kg to each bird. Blood samples were collected at 10 different time points from 0 to 30 hours postadministration to evaluate plasma levels of atorvastatin, para-hydroxyatorvastatin, and ortho-hydroxyatorvastatin. Pharmacokinetic analysis was performed using noncompartmental analysis and commercially available software.RESULTSMean +/- SD atorvastatin half-life, tmax, and Cmax were 5.96 +/- 11.50 hours, 1.60 +/- 0.80 hours, and 82.60 +/- 58.30 ng/mL, respectively. For para-hydroxyatorvastatin, the half-life, tmax, and Cmax were 6.46 +/- 54.20 hours, 5.00 +/- 2.51 hours, and 34.10 +/- 16.00 ng/mL, respectively, and 5.58 +/- 9.92 hours, 3.38 +/- 2.10 hours, and 7.35 +/- 3.96 ng/mL for ortho-hydroxyatorvastatin.CLINICAL RELEVANCEThe plasma concentrations and pharmacokinetic profile shown support the therapeutic use of atorvastatin at the dose evaluated in this species based on human pharmacokinetic data. While 20 mg/kg PO q24 hours could be used as a starting dosage until further studies evaluating multiple dose administration and efficacy in this species become available, the high interindividual variability results warrant monitoring of the treatment response to make dosing adjustments if needed.