Research recently carried out in America suggests that when paracetamol is taken in combination with coffee, an increased risk of damage to the liver could be generated. The study, entitled ‘Chemical Research in Toxicology’ was carried out by researchers at the University of Washington. However, the trials so far undertaken have been limited to the use of rats and bacteria. Consequently, says an expert in the UK, much more extensive research would be required before a human risk could be established.

While scientists are aware of the increased toxicity attached to paracetamol when combined with significant consumption of alcohol, the new US research marks the first time a paracetamol/caffeine combination has been suggested as dangerous.

In a large number of paracetamols on the market, Caffeine is an active ingredient.

The researchers at the University of Washington advise that, when taking paracetamol – the intake of caffeine should be kept to a minimum. As per the University’s Dr Sid Nelson: "The bottom line is that you don't have to stop taking acetaminophen [paracetamol] or stop taking caffeine products, but you do need to monitor your intake more carefully when taking them together, especially if you drink alcohol."

In the study, the bacteria E.coli was used, but in genetically-altered form. The modifications were made in order to generate a prime chemical which assists with deconstructing paracetamol once it enters the liver. When the bacteria was blasted with paracetamol and caffeine en masse, it produced toxic byproduct at three times the usual rate.

While conceding that, under test conditions, the amounts of caffeine and paracetamol used were over and above usual levels of daily human consumption, Dr Nelson said the threshold in relation to danger/safety within humans had not been deduced as of yet.

As far as the University of Newcastle’s Dr Simon Thomas was concerned, the research was at too premature a stage to warrant issuing any form of public health warning. "There are a million miles between E. coli and humans in terms of how paracetamol and caffeine are metabolised, he said.  

"This would be of considerable interest if it were true, but further research would have to be carried out first. Paracetamol overdose is still a major problem in the UK, accounting for 40% of all drug overdoses - leading to approximately 100 deaths or liver transplants a year."

Source – Pharmaceutical International’s US Reporter