Some reflections on positive results from medication control tests in the USA

This article describes 3 of the drugs responsible for positive tests in American racing in recent years: fentanyl, apomorphine and reserpine. Experimental work is described in which the effect of administration was measured objectively against step counting; other aspects of locomotor stimulation and clinical responses are discussed. The supposed tonic effects of “pangamic acid” are considered and attention is drawn to the view of the US Food and Drug Administration that the substance does not exist.