Brent, this is from the policy pages:

Proper and Improper Use of Prescription and Over-the-Counter
Medications/Substances
USAC recognizes that there are many prescription and over-the-counter medications that
serve essential or beneficial purposes for the health and well-being of Competitors and Officials,
and nothing in this Policy is intended to discourage the proper use of these medications. Just as
importantly, however, it must be recognized that there are some medications that, even when
properly used, may adversely affect a participant's fitness to be involved in a racing event or
events. For example, many types of cough medicines contain codeine, which is a potent narcotic
that may result in drowsiness or diminished alertness.
Misuse and the illegal use, acquisition or distribution of a prescription or over-the-counter
medication or any mind-altering or addictive substance by an individual is prohibited and, for these
purposes, is deemed to be the use of such a medication in a manner which is inconsistent with the
instructions provided by the manufacturer, pharmacist and/or the prescribing physician. In
addition, illegal use, acquisition, or distribution of any prescription
drug, over-the-counter medication, or any mind-altering and/or addictive substance are strictly
prohibited at any time. For example, it is a violation of this Policy for an individual to use a
prescription or over-the-counter medication in a manner that is not consistent with the intended and
medically-prescribed use.
To the extent that USAC in its sole discretion determines that the use of any prescribed
medication or other substance, including properly prescribed prescription drugs and properly used
over-the-counter medications, causes an individual to have a diminished or impaired ability to
perform his or her duties on the day of an Event, those substances shall be deemed to be prohibited
substances for purposes of this Policy.