Mixing energy drinks and alcohol is incredibly dangerous. As a stimulant, caffeine masks the depressive effects of alcohol, confusing the drinker, who doesn’t feel as inebriated and therefore drinks more than he or she should.
According to the Centers for Disease Control and Prevention (CDC), “Drinkers who consume alcohol mixed with energy drinks are 3 times more likely to binge drink (based on breath alcohol levels) than drinkers who do not report mixing alcohol with energy drinks.” They are also twice as likely to be taken advantage of sexually, to take advantage of someone else sexually, and to ride with a drunk driver.
One study found that people who mixed alcohol and energy drinks were four times as likely to think they could drive home (compared to those who drank alcohol on its own). And a survey of 500 students at the University of Michigan showed that students who drank alcoholic energy drinks reported two to three times as many negative consequences (passing out, having a hangover, etc.) versus those who stuck to just alcohol.
In 2010 the FDA banned premixed alcoholic energy drinks such as Four Loko, which contained the equivalent of four beers’ worth of alcohol and one-to-two cups of coffee. But in 2011, there were still 2,600 emergency room visits involving alcohol and energy drinks—a testament to the myriad hazards of mixing these substances, each of which is dangerous enough on its own.