There is only one safe rule to follow with respect to combining flying and drinking - don't. Alcohol consumed by a person is metabolized at a fixed rate by the body. This rate is not altered by the use of coffee or other popular "quack" remedies. Hangovers, whether masked by aspirin or other medication are included in the preceding admonition about flying.
Recent medical investigations of general aviation accidents indicate that alcohol has been a factor in a significant number of aircraft accidents. The inherent danger in drinking and flying apparently has not impressed some pilots. Possibly they labor under the deadly delusion that flying after a few drinks is no more dangerous than driving while in the same condition. (Even this would be a false assumption since drinking is involved in about half the fatal auto accidents investigated.)
We must first accept two simple truths. First, flying an airplane is more complex than the two dimensional demands of driving a car. Second, increased altitude multiplies the intoxicating effect of alcohol on the body.
For all practical purposes, only the brain gets "drunk." When a person drinks an alcoholic beverage, the alcohol begins immediately to pass from the stomach to the bloodstream. Two ounces of bourbon will be absorbed by the bloodstream in ten minutes, four ounces in thirty minutes, and eight ounces in one and one-half hours. The alcohol is carried by the bloodstream to all parts of the body with varying effects, but the brain is really affected the most. Alcohol numbs the brain in the area where our thinking takes place, then proceeds to the area that controls ordinary body movements. Coordination is affected, eyes fail to focus, and hands lose their dexterity.
Any pilot who flies within 8 hours after the consumption of alcoholic beverages or while under the influence of alcohol, is not only dangerous but is in violation of Federal Aviation Regulations.