Medication control: Rules

The simplest medication rule is a “no detectable level” rule. This rule is used in much of Europe and North America. The principal problem with this rule is that it is virtually impossible to give any guidance to horsemen as to when they should cease drug administration. Part of the reason for this is that the analyst can change the rule at will, simply by changing his detection method.A much more equitable rule is one that specifies a blood or urinary tolerance for a drug. When a tolerance is specified, changing the test method is of no significance, and guidelines can be given to horsemen to help them comply with the rule. The National Association of State Racing Chemists' tolerance for phenylbutazone is a classic example of such a rule.Both of these rules have the advantage that the event which defines the violation is objective and independently verfiable. In each case, the drug can be detected or quantitated by an independent analyst. Independent confirmation removes all doubt as to the scientific basis of the regulatory action.Time rules specify times prior to post during which drugs cannot be administered. While such rules read well and are easy to write, they are troublesome to enforce. This is because enforcement of a time rule depends not on a measured blood or urinary drug level, but rather on an analyst's opinion as to when the drug was administered. This opinion will always have a probability of error, which may be greater, for example, than the number of horses that the analyst tests per year. Under these circumstances, the horsemen's testimony may be correct, and the analyst's opinion incorrect, in a significant proportion of cases. No objective, independent check of the analyst's opinion is possible, and neither are contrary opinions independently verifiable. Such a regulatory process is unsatisfactory and may undermine the credibility of the analyst.Because of the technical difficulty and expense of medication control, the strategy of no control for some medications is an option which requires careful evaluation.