Immunoassay detection of drugs in racing horses. XI. ELISA and RIA detection of fentanyl, alfentanil, sufentanil and carfentanil in equine blood and urine.

The researchers have developed a quick and cost-effective test that can detect the presence of certain narcotic analgesics such as fentanyl, sufentanil, carfentanil, and alfentanil in the blood and urine of racehorses.

Objective Overview and Methodology

• The present study focuses on the development and evaluation of a one-step enzyme-linked immunosorbent assay (ELISA) test for sufentanil and a 125I radioimmunoassay for alfentanil.
• The tests are part of a panel of pre-and post-race tests designed to detect narcotic analgesics in racing horses.
• The proposed tests are aimed at improving the quality of these detections while reducing associated costs.

Results of the Sufentanil ELISA Test

• The sufentanil ELISA test developed by the researchers detects sufentanil with an I-50 of about 0.5 ng/ml, making it sensitive enough for reliable detections.
• The test is rapid and economical, with results that can be read with an inexpensive spectrophotometer or visually.
• The sufentanil ELISA test can detect the presence of sufentanil or its metabolites in the horse’s blood and urine from 1 to 24 hours after either therapeutic or sub-therapeutic doses of the drug have been administered.
• It also cross-reacts with fentanyl, designer fentanyls, and carfentanil, allowing the test to detect these drugs in the urine of horses for several hours post-administration.
• This test does not, however, cross-react significantly with alfentanil, necessitating the development of a separate test for the latter.

Results of the 125I Radioimmunoassay Test for Alfentanil

• A 125I radioimmunoassay has also been developed by the researchers specifically for alfentanil detection.
• The test allows for the detection of alfentanil in the blood and urine of horses for up to 4 hours post-administration.

Overall Implication

• The tests developed are effective in improving the quality and reducing the costs of narcotic analgesics testing for fentanyl, sufentanil, carfentanil, alfentanil and their congeners in racing horses, both before and after races.
• These tests can also be effectively utilized for screening these drugs in human drug abuse monitoring, thereby enhancing their applicability and utility beyond equine contexts.