Long-term and regular use of Paracetemol has been linked with increased heart attack and stroke risks among people with high blood pressure.

Researchers at the University of Edinburgh have recommended that Doctors should think about the risks and benefits to patients taking it over many months.

Paracetamol is used widely internationally as a short-term remedy to various aches but it can also be prescribed to manage chronic pain.

One out of every 10 people in Scotland - half a million people -  were prescribed the painkiller in 2018.

The Herald: Paracetamol pills and packaging. Credit: PAParacetamol pills and packaging. Credit: PA

What did the Paracetamol study reveal?

The study tracked 110 volunteers, which included two-thirds of the participants taking drugs for high blood pressure, or hypertension.

In the randomised trial, they were asked to take 1g of paracetamol four times a day for two weeks which is a common dose for patients with chronic pain.

They were then given placebo pills for a further two weeks.

The trial indicated that paracetamol increased blood pressure, "one of the most important risk factors for heart attacks and strokes" - much more than a placebo, Edinburgh clinical pharmacologist Prof James Dear said.

Is Paracetamol safe to take over the long term?

Scientists maintain that taking a painkiller for the likes of fevers and headaches is safe.

Lead investigator Dr Iain MacIntyre, clinical pharmacology consultant, at NHS Lothian, said: "This is not about short-term use of paracetamol for headaches or fever, which is, of course, fine."

Experts simply say that more research across more people over a longer time period is needed to confirm the findings in the report.

"Firstly, it is not clear whether the observed increase in blood pressure would be sustained with longer-term use of paracetamol," Dr Dipender Gill, clinical pharmacology and therapeutics lecturer, at St George's, University of London said.

Dr Dipender Gill  maintained that "many unknowns remain" following the study and continued by saying: "Secondly, it is not known for certain whether any increase in blood pressure attributable to paracetamol use would lead to an increased risk of cardiovascular disease."

The Edinburgh study is not the first to look into the long-term use of the painkiller.

A large US study previously identified a link between long-term paracetamol use and increased risk of heart attacks - however, it could not prove that one caused the other.

Smaller studies have also been conducted which have also been unable to confirm the link.

What's next for the Paracetamol study?

While the Edinburgh researchers could not explain how paracetamol could raise blood pressure, they have said their findings should lead to a review into long-term paracetamol prescriptions.

Further research into people with normal, healthy blood pressure, over a longer time period, is required "to confirm the risks and benefits of using paracetamol more widely," Dr Richard Francis, from the Stroke Association, said.

Expert advice on Paracetamol

Following the study, the researchers have advised Doctors to start patients with chronic pain on as low a dose of paracetamol as possible.

Doctors should also keep a close eye on patients with high blood pressure and who are at risk of heart disease.

"If you are concerned about the risks from pain medicines you should speak with a healthcare professional to explore your options." said Dr Benjamin Ellis, a consultant rheumatologist at Versus Arthritis.

For more information about Paracetamol, including side effects and other advice, visit the NHS website.