There have been dramatic public policy developments surrounding caffeinated alcohol beverages since Michelle Brandt wrote about them here less than a month ago. Half a dozen states have banned or announced plans to ban "black out in a can," as these drinks are sometimes called. Today, the FDA issued a warning letter to manufacturers of these products, one which has already announced that it will remove caffeine from its popular and potent drink "Four Loko."
Consuming stimulants (e.g., cocaine) with alcohol is a common practice among heavy drinkers. Many heavy drinkers find the combination reinforcing because the stimulant wards off some of the negative subjective effects of alcohol (e.g., drowsiness) and in some cases may result in a unique third chemical reward in the brain - cocaine and alcohol, for example, combine to create a drug known as cocaethylene that creates an extended feeling of euphoria.
The minimization of alcohol's subjective negative effects makes the combination of stimulants and alcohol more rather than less dangerous. In experiments on perception and reaction time, people who consume alcohol and caffeine show the same deficits as those who just drink alcohol, but they are not as aware of them. It thus seems subjectively more reasonable to the consumer of combined alcohol and caffeine behaviors to have a few more drinks because they don't feel very intoxicated. They are also more likely to overestimate their ability to engage in tasks involving concentration, perception and coordination, such as driving a car down a busy interstate at night. More information on the health risks of these beverages is available in a letter (.pdf) to state attorneys general written by some leading scientists, who concluded that adding caffeine to alcoholic beverages did not meet FDA's "generally recognized as safe" (GRAS) standard.
Does the regulatory action by states and the FDA end this problem, for example, on the many college campuses where these beverages are quite popular? Not entirely. Removing the cheap, heavily promoted pre-mixed products form the shelves is a significant victory for public health, but some drinkers will continue to buy a few cans of Red Bull along with their vodka and produce a homemade version of Four Loko. To further constrain the health damage of combined alcohol and stimulant use, public education by health officials, clinicians and college administrators will be required, as will public health warnings and potentially further regulation at points of sale.
Keith Humphreys, PhD, is a professor of psychiatry and behavioral sciences at Stanford and a career research scientist at the Palo Alto VA.