Effect of food restriction (undernutrition) on pharmacokinetics of levonorgestrel in rabbits

Abstract

Twelve female rabbits aged about 3–4 months were randomly divided into two groups (group A and group B) and were individually matched for their initial body weights. Animals of group A received a stock diet ad libitum while each of the animals in group B were fed 50% of the diet consumed by the corresponding matched control from group A. Pharmacokinetics of levonorgestrel were determined in all animals between 1 1 2 –2 months after these diets were started, using an intravenous dose of 8–20 μC i of 3H-levonorgestrel and 15–20 μg of levonorgestrel per kg body weight. Urinary excretion of radioactivity was also measured in all the animals for a period of 5 days following the dose. The body weights of animals on the restricted diet were 17% lower than those of the ad lib fed animals. Haemoglobin levels and plasma albumin concentration were found to be in the normal range in both groups. There was a significant increase in Metabolic Clearance Rate (MCR) and t 1 2 π and a decrease in elimination half-life in animals of group B as compared to those seen in animals of group A. The urinary excretion of label was found to be slightly increased in group B animals as compared to that in group A controls.