Effects of sodium bicarbonate and sodium chloride on the elimination of etorphine in equine urine.

The research examines how giving racehorses large doses of sodium bicarbonate and a potent drug called etorphine could potentially enhance their performance and make it harder to detect the presence of etorphine in horse urine.

Research Design and Methodology

• The researchers constructed an experiment to explore the effects of this drug combination on racehorses. Their subjects were six Thoroughbred horses.
• A Latin-square design was applied, which split the horses into three pairs. Each pair was given one of three treatments: etorphine alone, etorphine with sodium bicarbonate, or etorphine with sodium chloride.
• The purpose of using sodium chloride was to discern between the urinary alkalinization properties of sodium bicarbonate and the diuretic effects linked to the large load of electrolytes.
• Blood and urine specimens were gathered from the horses before the treatment and continued for 24 hours afterward.

Findings

• Administration of sodium bicarbonate caused a significant metabolic alkalosis, a condition in which the body’s pH levels rise and become too alkaline. It also increased the pH level of the horses’ urine.
• Both sodium bicarbonate and sodium chloride induced profound diuresis or increased urine production. This is crucial as it could dilute the concentration of etorphine in the urine, making it harder to detect.
• The concentration of etorphine in the horses’ urine decreased following the sodium bicarbonate and sodium chloride treatments. It was measured by a technique called radioimmunoassay (RIA). In some instances, the etorphine could not be traced at all.
• When the researchers extracted the urine samples prior to the RIA analysis, the test’s sensitivity improved. In most cases, it resulted in a positive detection of etorphine.

Conclusion

• The research concludes that administering etorphine with either sodium bicarbonate or sodium chloride could complicate the detection process of etorphine due to the dilutional effects from the large electrolyte load.