The curious case of energy drinks & hypokalemia
Published in the journal Anaesthesia Critical Care & Pain Medicine, the paper describes an incidence of hypokalemia in a 28-year-old man at the Military Hospital of Dakhla in Morocco.
Hypokalemia is the deficiency of potassium in the bloodstream.
The otherwise healthy man was admitted to the emergency department because of thirst, sweating and nausea.
He had drunk four cans (1000 ml) of the energy drink Burn within three hours in preparation for a 19-hour drive.
Earlier this year the European Food Safety Authority (EFSA) set the safe upper limit of 400 mg of caffeine a day and 200 mg in a single session over two hours.
An average cup of coffee contains around 95 mg.
When admitted the man had serum potassium levels of 2.12 mmol/L but IV hydration with potassium improved the symptoms of thirst and nausea and increased serum levels to 3.92 mmol/l after 15 hours.
According to the UK’s National Health Service (NHS), the normal serum range is 3.5 – 5.3 mmol/L and below 2.5 mmol/L is classed as “severe” hypokalemia.
The same NHS guidance document lists caffeine among agents that may cause hypokalemia.
The man stayed in the intensive care unit for 48 hours on an IV drip.
“The absence of other ingested substances or conditions makes the energy drink the most likely cause of hypokalemia in this case report,” they concluded in the report.
“This case highlights the need for clinicians to recognise hypokalemia as a potential life-threatening consequence of abusive energy drink ingestion and the need to report such side effects to competent regulatory authorities.”
They said the mechanisms behind these ionic declines remained unclear however it could be related to antagonism of adenosine receptors or alternatively a movement of potassium into cells.
A history of reports
This is not the first case of hypokalemia linked to excessive energy drink consumption.
In 2010 doctors from the Box Hill Hospital, Melbourne, Australia reported “an unusual and emerging cause of profound hypokalaemia” associated with a severe myopathy – disease of muscle tissue – possibly caused by the misuse of painkiller Nurofen Plus and excessive consumption of the caffeine-containing energy drink, Red Bull.
Another case study of hypoglycaemia in a diabetic patient after high energy drink consumption also pointed to the risk of hypokalemia.
The case study said potassium was required for glucose to enter cells, meaning high doses of sugary energy drinks could induce the condition.
French concerns struck off by EFSA
Hypokalemia was flagged in a 2013 report from French Agency for Food, Environmental and Occupational Health & Safety (ANSES) as among possible health issues relating to energy drink consumption.
In 2013 ANSES analysed 212 cases of all adverse effects reported through its Nutritional Vigilance Scheme.
It concluded a causal relationship between the consumption of 'energy drinks' and adverse health effects was 'very likely' or 'likely' in 25 cases (12%) and possible in 54 (24%).
EFSA did not include such medical case reports in its final 2015 safety opinion nor did it address hypokalemia.
Speaking at the time it said they were limited in value due to poor reporting that often did not account for other substances consumed.
It added that the assessment was not meant to account for the ‘abuse’ of energy drinks, but look at consumption within normal ranges.
The German Federal Institute for Risk Assessment (BfR) said this ignored what was actually happening on the ground, such as high energy drink and alcohol consumption among young people in nightclubs.
Burn, a Coca-Cola product, is available in 76 markets throughout Europe, Africa and the Americas.
Coca-Cola did not respond to our request for comment in time for the publication of this article.
Andreas Kadi, secretary general of trade association Energy Drinks Europe (EDE), told us there was nothing unique about caffeine found in mainstream energy drink, which was often comparable to a cup of coffee.
“The safety of energy drinks has been established by scientific research as well as regulatory agencies around the globe. Just this year the European Food Safety Authority (EFSA) confirmed the safety of energy drinks and their ingredients after an extensive review.
"Even so, America’s leading energy drink manufacturers voluntarily go far beyond all federal requirements when it comes to responsible labeling and marketing practices, including displaying total caffeine content – from all sources – on their packages along with advisory statements indicating that the product is not recommended for children, pregnant or nursing women and persons sensitive to caffeine,” he said in response to this case study
Source: Anaesthesia Critical Care & Pain Medicine
Volume 34, Issue 5, Page 303, doi:10.1016/j.accpm.2015.05.002
“An unexplained hypokalemia: Consider energy drinks”
Authors: K. Mounir, M. Mattous and M. Atmani
