Researchers have warned that mixing alcohol with energy drinks can seriously increase the risk of injury.
Popular cocktails like Jagerbombs, espresso martinis and vodka and red bull can be more dangerous than drinking alcohol on its own.
Scientists believe the stimulating effect of caffeine encourages people to stay out longer and drink more volumes of alcohol, according to a review of 13 academic studies.
Study leader Audra Roemer likened the effect of mixing the two drinks to taking cocaine and warned it "could be a serious public health concern".
"Cocaine is obviously a strong stimulant, and I was curious about lower level stimulants that are more socially acceptable.