Influence of age on pharmacokinetcs of orally administered nitrofurantoin and furazolidone in buffalo

The present work aims at studying the disposition kinetics of single doses of nitrofurantoin [NFT] and furazolidone [FZ] in buffalos of different ages. The experiments were conducted on animals of 6-8 years, 2-12 months and less than 2 months old. The pharmacokinetic analysis of the determined levels of the two tested drugs during 24 hours following their administration has showed age-dependent variations. The rate constant of elimination [Kel] was decreasing with the increase of age with a consequent prolongation of the elimination half life [tB 1/2]. As a net result of the different induced changes in pharmacokinetics, the area under the plasma level curve has been markedly decreased in the young age animals. As a conclusion, dosage regimens of NFT and FZ in buffalo calves should be adjusted according to the age of the animals