The enduring quest for the ideal, legal high has stumbled yet again.
Four manufacturers of alcoholic energy drinks were issued warnings Wednesday by the Food and Drug Administration (FDA). The federal agency found caffeine is an "unsafe food additive" in alcoholic beverages.
The decision empowers the government to seize the products if companies continue to produce them.
Prior to the government prohibition, the manufacturer of one popular alcoholic energy drink, Four Loko, decided to remove the caffeine kick from its beverage.
The mood-altering concoctions contain as much as 12 percent alcohol, the equivalent for four beers, combined with the caffeine equivalent of about three cups of coffee.
Four Loko's creators attributed their caffeine-removal decision to what they characterized as "a difficult and politically charged regulatory environment at both the state and federal levels."
The regulatory environment escalated with the FDA decision, which came in the wake of prohibitions already imposed by a number of states, including Washington, Michigan, Utah and Oklahoma.
Although medical and scientific evidence about the alcohol-caffeine combinations is scant, health officials warn the drinks can make people feel more alert and capable of handling tasks like driving.
A study at Wake Forest University determined students who combine alcohol and caffeine are more likely to suffer alcohol-related injuries than those drinking alcohol without caffeine.
Anecdotal evidence from college campuses supports those findings. A variety of colleges throughout the nation have reported hospitalizations and accidents involving students who consumed the alcoholic energy drinks.
Prohibition of the beverages may inconvenience - but won't deter - people intent on getting falling-down drunk.
Beyond that, the health and public safety consequences of ingesting large amounts of alcohol and caffeine in a single drink can be not only troublesome, but deadly.