A dangerous combo - schoolies warned

Pharmacy researchers at the University of Sydney are warning HSC students to take it easy on caffeine, alcohol and smoking during Schoolies Week, particularly young women using oral contraception.

The researchers say there are hidden dangers in combining energy drinks, alcohol, oral contraceptives and smoking.

A daily consumption caffeine of around two to three cups of coffee combined with cigarette smoking significantly increases the activity of the metabolising enzyme known as CYP1A2. Found in the liver, CYP1A2 is responsible for processing a number of chemicals ingested when we eat or drink, according to Vidya Perera, a final-year PhD student in the Faculty of Pharmacy who is studying the mechanisms of the enzyme.

Perera’s research on CYP1A2, which is aimed at understanding the correct dosage of a drug or pharmaceutical, has found a 1.8 fold decrease in metabolising enzyme’s activity in women who use oral contraception compared to females not using the pill.

But his work has also found an increased level of activity of CYP1A2 in women who both smoke and drink caffeine.

"Use of the oral contraceptive pill among young women inhibits the enzyme CYP1A2 responsible for metabolising caffeine and it can be reduced in some women by up to five-fold. This means that caffeine is staying in your body for a lot longer than women not taking the pill," says Perera.

"Young women who are unaware of the risks that are involved with alcohol consumption, caffeine, smoking and being on the oral contraceptive pill could find themselves behaving abnormally. In a party or celebratory situation people often challenge each other to a ’drink for drink’ or have rounds together, but if one young woman is taking the pill and others are not, after three or four drinks of these mixed alcohol and caffeine cocktails, the one on the pill is going to be feeling quite ill due to the excessive caffeine build-up."

Commonly, caffeine causes excitability, and in larger quantities, irregular and rapid heartbeat, flushing and hyperactivity. Perera says young women on an oral contraception run the risk of becoming hyperactively drunk.

"Young women need to be aware that if they drink alcohol and begin feeling a little sick, it’s not because they are ’soft’, their body is probably telling them to stop," states Perera.

The effects of large amounts of caffeine in the long term are still being investigated but it has been linked to cardiac issues in older age, while increased CYP1A2 activity has been linked to several cancers.

A series of deaths and hospitalisations due to excessive consumption of ’mixed’ energy and alcoholic drinks prompted close scrutiny of the selling of these types of drinks. The Western Australian government has banned the selling of these drinks after midnight while several death related incidence prompted the Food and Drug Administration in the United States to warn four companies that caffeine added to malt alcoholic beverages was an ’unsafe food additive’.

The latest Australian Bureau of Statistics figures indicate as many as nine percent of young women between the ages of 15 and 24 smoke regularly.