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Pemoline And Tetramisole 'Positives' In English Racehorses Following Levamisole Administration, J. Gutierrez, R. L. Eisenberg, N. J. Koval, E. R. Armstrong, J. Tharappel, C. J. Hughes, Thomas Tobin

Veterinary Science Faculty Publications

Pemoline is a central nervous system stimulant that has been used to treat attention-deficit hyperactivity disorder and narcolepsy in humans; its identification in horses could be considered evidence of attempts to influence performance. Two recent pemoline 'positives' in English racehorses led us to review the chemical relationships between tetramisole, levamisole, aminorex and pemoline. Pemoline is a simple oxidation product of aminorex, which has been shown in the United States and elsewhere to be an equine metabolite of levamisole. Based on the clear structural relationships between aminorex and pemoline, we conclude that levamisole can metabolise to pemoline in horses and that …