Update: Since the story broke of Athéna Gervais's death, Health Canada has addressed concerns raised about the amount of caffeine in sugary, alcoholic drinks such as FCKD UP. On the issue of caffeine levels in this beverage, the department says one 568 mL can of FCKD UP contains 1 mg of caffeine. By comparison, one cup of coffee contains anywhere between 70 mg and 180 mg of caffeine.

Manufacturers on Sunday halted production of the caffeinated, high-alcohol drink FCKD UP amid outcry over the death of a 14-year-old girl in Laval, Que.

An unidentified friend told Montreal's La Presse newspaper that Athena Gervais had at least one can of the malt liquor-based beverage during her school's lunch hour before her disappearance. Her body was pulled from a stream near her school four days later.

While police haven't confirmed that information, as they are still awaiting a toxicology report to determine if Athena had been drinking, the teen's death has brought such drinks — known as caffeinated-alcoholic beverages (CABs) — under renewed scrutiny.

Doctors, politicians and public health officials are especially concerned about their popularity among young people.

"We feel that this is a problem that is, in fact, growing right now," said Martin Laliberté, a toxicology specialist with the McGill University Health Centre and head of the Canadian Association of Poison Control Centres.

Here is a closer look at the issue.

What is the danger of these drinks?

CABs are basically pre-made mixes of an energy drink with high-content alcohol, usually above nine per cent. They are sold widely in convenience stores — and usually at cut-rate prices.

Public health authorities across North America have issued warnings about these drinks for close to a decade, linking them to a large number of health incidents.

Several public health officials have singled out the marketing of CABs as being particularly problematic. (Radio-Canada)

A study by the U.S.-based Center for Behavioral Health Statistics and Quality estimated that the number of emergency room visits related to energy drinks doubled between 2007 and 2011. Of those visits, between 13 and 16 per cent were attributed to mixing energy drinks with alcohol.

One theory explaining this phenomenon is an effect produced by the combination of alcohol and caffeine known as an "awake-drunk state." Experts believe the caffeine, a stimulant, works to mask the normally depressive effect of alcohol.

"That is what we think is resulting in people staying out longer, staying out later, thinking that they're more sober than they are because they're not getting that sleepy-drunk effect," said Audra Roemer, a PhD student at the University of Victoria and co-author of a recent study on the health effects of mixing energy drinks with alcohol.

"They maybe think they can have a couple more drinks, or maybe drive home drunk. Those are behaviours that often result in people getting hurt. They're behaving in a way where they believe they're sober, when they're not."

Why are these drinks legal?

Health Canada forbids caffeinated energy drinks from containing alcohol. Nor can alcoholic drinks contain caffeine.

But a loophole exists. Alcoholic drinks are allowed to have flavouring ingredients that naturally contain caffeine.

This is why FCKD UP could be sold in stores in Quebec. It was flavoured with guarana, a plant that contains caffeine, as opposed to caffeine itself.

"Flavouring agents, including those that naturally contain caffeine, must be declared on the list of ingredients. Flavourings, including guarana extract flavouring, do not have regulatory limits; rather, the amount that can be added is limited by palatability," Health Canada spokesperson Eric Morrissette told CBC in an email.

Although FCKD UP is being pulled from shelves across the province, similar beverages are still available for sale. That's the case with REV UP, a drink made by the same company behind FCKD UP, Geloso Group. It has 10 per cent alcohol and also contains guarana.

What have other jurisdictions done?

In 2010, the U.S. Food and Drug Administration told seven CAB makers that the presence of caffeine in their drinks was making them unsafe and that they could no longer be sold in their current form.

Several of the manufacturers complied by removing caffeine and were able to continue selling their products. These drinks, however, continue to have sugar levels comparable to other energy drinks.

In Canada, some jurisdictions have attempted to discourage the manual mixing of alcohol with energy drinks. Liquor stores in Alberta and Ontario, for example, are prohibited from selling energy drinks.

Several municipalities across the country have banned all energy drinks, including those containing alcohol, in city-owned buildings.

Quebec Public Health Minister Lucie Charlebois said she is concerned about how easy it is for young people to buy drinks like FCKD UP. (CBC)

Who is responsible for making changes?

Health Canada has jurisdiction over what is allowed to go into food and beverages in the country. The Quebec government is pushing the federal ministry to impose stricter regulations on caffeinated alcoholic beverages.

"Health Canada has to quickly intervene in regards to these drinks (CABs) and determine their safety," Premier Philippe Couillard said Tuesday. "I want them regulated."

For its part, Health Canada pointed out that provinces have jurisdiction over where alcohol is sold and to whom. Provinces also have control over how alcoholic products are advertised.

Several public health officials have singled out the marketing of CABs as being particularly problematic.

"I suspect the marketing is actually targeting the younger crowd, a crowd that is not even of legal age to drink," said Laliberté, the MUHC toxicology specialist.

"These drinks present a very, very high risk for the young population," he said. "I would actually go so far as saying that these risks they present is inappropriate. It's unacceptable."