Alcohol Concern is urging drinkers to be more aware of the potential risks of mixing alcohol with energy drinks.
In its new briefing paper Mixed Messages the charity highlights the possible dangers of mixing highly caffeinated drinks with alcohol.
In particular, the caffeine in energy drinks can mask the effects of alcohol, meaning that drinkers may be less aware of how drunk they are, and more likely to put themselves in danger.
Sales of energy drinks have shot up in the UK in recent years, particularly among young people, but there is a general lack of guidance about the dangers of mixing high-caffeine drinks with alcohol.
Many drinkers may be unaware just how much caffeine they're taking in. A 500ml can of an average energy drink such as Rockstar, Relentless or Monster contains 160mg of caffeine. That's the equivalent of a double espresso or five cans of Coca-cola
Both caffeine and alcohol are diuretics - they cause the body to pass water - so mixing energy drinks with alcohol can leave drinkers badly dehydrated, possibly leading to vomiting, nausea, and other health problems in the long term.
What's more dangerous, perhaps, is that the stimulant effect of so much caffeine can mask the depressant effect of the alcohol. People drinking energy drinks with alcohol may feel very alert and not realise how drunk they are. One possible result of this is that drinkers will take more risks.
A study in the USA found that students drinking alcohol mixed with energy drinks were four times more likely to intend to drive compared with drinkers who had consumed alcohol without energy drinks.
We're keen to give drinkers the heads-up on the effects of mixing caffeine and energy drinks through our Drink Wise Wales website. Our aim is to give people the correct information about the dangers associated with alcohol so they can make informed and healthy drinking choices.Andrew Misell from Alcohol Concern
Alcohol Concern Wales's Drink Wise Wales website contains an alcohol and energy drink counter outlining the amount of alcohol, caffeine and sugar in common energy drink cocktails such as a double vodka and Red Bull, a Jägerbomb (Jägermeister shot with Red Bull), and a TVR (tequila, vodka and Red Bull).
Alcohol Concern is also challenging producers and retailers of energy drinks to act more responsibly. The charity is calling on energy drink producers to actively communicate the possible dangers of mixing their products with alcohol in their marketing and advertising campaigns, and is urging bars and clubs to stop promoting energy drinks as mixers for alcohol.