That is the problem. Narcotic pain killers of the opioid variety can very much contribute to drowsiness and inhibit reflexes... in non tolerant individuals.
Well, you have to pick your poisons. We've found that a few lines of coke before a 2 hour stint in the enduro car just doesn't produce the results that it does in a 20 lap sprint.

An interesting question to the drivers on this site would be, would you feel comfortable competing on track with a driver whom you knew was a long term pain management patient??
Anyone thoughtful enough to publicly ask the question is better in my book than the guy who takes his medical form to the ER gets it signed and never tells the Dr or SCCA that they are trying to be Hunter Thompon's understudy.