Evaluation of Orally Administered Atorvastatin on Plasma Lipid and Biochemistry Profiles in Hypercholesterolemic Hispaniolan Amazon Parrots (Amazona ventralis).

Abstract

Atorvastatin is a synthetic statin administered in its active form and used for the treatment of dyslipidemias. In the current study, the effects of atorvastatin were evaluated on plasma lipid profiles and the potential for adverse effects after once daily PO dosing of atorvastatin for 30 days in Hispaniolan Amazon parrots (Amazona ventralis). Sixteen adult parrots (10 female, 6 male) with hypercholesterolemia were used for this study. Birds were assigned to 2 groups (treatment and control) of 8 parrots each (3 male, 5 female) after balancing for age, sex, originating institution, and baseline plasma cholesterol values. Compounded atorvastatin oral suspension (10 mg/kg) was administered PO once daily via gavage into the crop. Equivalent volumes of placebo suspension were administered to the control group. Plasma biochemistry and plasma lipid profile analysis (total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides [TGs]) were analyzed on days 0, 14, and 30. Plasma samples and HDL-C fractions were evaluated for cholesterol and TG concentrations via enzymatic assays. Subtraction of HDL-C values from total cholesterol yielded the non-HDL-C concentration for each bird. Birds were routinely assessed for appetite, activity, and urofeces. Plasma atorvastatin concentrations were obtained from 7 of 8 birds in the treatment group from banked samples. Those samples were obtained on days 14 and 30, with drug administration 6 to 8 hours before collection. No significant differences were observed in total cholesterol, HDL-C, non-HDL-C, or TG between treatment and control groups at days 0, 14, and 30. Plasma atorvastatin concentrations were variable on day 14 (0.54-5.41 ng/ mL for 6 of 7 samples, with 1 outlier of 307 ng/mL) and on day 30 (0.79-6.74 ng/mL). No adverse effects were noted in any of the birds during the study period. When dosed PO at 10 mg/kg once daily, atorvastatin did not result in significant changes to plasma lipid profiles (eg, lowering of plasma total or non-HDL-C concentrations) at any time point during this study. Future studies to investigate pharmacokinetic and pharmacodynamic properties of atorvastatin in parrots may require increased doses and/or frequency of administration.