Development and validation of analytical methods to study the performance enhancing effects of caffeine and guanabenz in fit thoroughbred horses

An HPLC method was developed and validated for the detection and quantification of caffeine and its metabolites in equine serum and urine samples. The method satisfied all predefined criteria for linearity, accuracy, precision, specificity, and sensitivity.; A study was designed to test the hypothesis that an intravenous dose of 2.5 mg/kg caffeine would affect the performance of Thoroughbred horses during incremental exercise testing to exhaustion on a treadmill.; Ten conditioned Thoroughbred horses were randomly assigned to receive caffeine or placebo. Each horse received both treatments in a crossover design. An incremental exercise test to exhaustion was carried out one hour after administration of drug or placebo. Heart rate, oxygen consumption, carbon dioxide production, plasma lactate, speed at failure, exercise duration, and urine and serum levels of caffeine and metabolites were monitored. No significant differences (p > 0.01) were found between placebo-treated and caffeine-treated horses for any of the measured variables.; An ELISA method was developed and validated for the detection and quantification of guanabenz in equine serum and urine samples. The method satisfied all predefined criteria for linearity, accuracy, precision, specificity, and sensitivity.; A study was designed to test the hypothesis that an intravenous dose of 0.08 mg/kg guanabenz would affect the performance of Thoroughbred horses during incremental exercise testing to exhaustion on a treadmill. Twelve conditioned Thoroughbred horses were randomly assigned to receive guanabenz or placebo. Each horse received both treatments in a crossover design. An incremental exercise test to exhaustion was carried out one hour after administration of drug or placebo. Heart rate, oxygen consumption, carbon dioxide production, plasma lactate, plasma catecholamines, ACTH, time to fatigue, and urine and serum levels of guanabenz were monitored. No significant differences (p > 0.01) were found between placebo and guanabenz treated horses for any of the measured variables.; These studies represent the first pharmacokinetic and exercise performance data obtained for these drugs in fit Thoroughbred horses during incremental exercise testing to exhaustion on a treadmill.