Repeated doses of paracetamol in older patients can lead to an increased risk of several severe complications, researchers have reported.

An analysis of 20 years of GP data found an increased risk of gastrointestinal, cardiovascular and renal complications associated with regular use of the painkiller.

The researchers from the University of Nottingham said the findings highlighted that care must be taken when used regularly for chronic conditions such as osteoarthritis.

Analysis of health records from 180,483 people over the age of 65 years who had been prescribed paracetamol repeatedly (≥2 prescriptions within six months) and 402,478 controls of the same age found an increased risk of peptic ulcers, heart failure, hypertension and chronic kidney disease.

The study also identified a dose-response relationship for paracetamol use and perforation or ulceration or bleeding, uncomplicated peptic ulcers, and chronic renal failure.

That pattern was the same when researchers only looked at the patients who had taken paracetamol, they reported.

It is also difficult to calculate exposure when most people take paracetamol episodically or for multiple reasons, they added.

A subgroup analysis focusing on patients with osteoarthritis also aligned with the overall findings, the researchers reported in Arthritis Care and Research.

The team did note they could not account for paracetamol bought over the counter which is why they focused on those who would have received free prescriptions.

Study leader Professor Weiya Zhang, from the NIHR Biomedical Research Centre at the University of Nottingham, said to its perceived safety that paracetamol has long been recommended as the first-line drug treatment for osteoarthritis by many treatment guidelines, especially in older people who are at higher risk of drug-related complications.

Yet their findings further challenge ‘whether acetaminophen should be retained as the first-line oral analgesic’, especially in older people for common chronic painful conditions, given its non-clinically meaningful benefits and potential harms, he concluded.

It also supports recent recommendation by NICE to not prescribe paracetamol for osteoarthritis, he added.

‘Whilst further research is now needed to confirm our findings, given its minimal pain-relief effect, the use of paracetamol as a first line pain killer for long-term conditions such as osteoarthritis in older people needs to be carefully considered.’

This article was first published by our sister title Pulse