People who regularly take high doses of commonly used anti-inflammatory painkillers, such as ibuprofen and diclofenac are at greater risk of a heart attack, new research shows.
Those with severe arthritis often take the drugs, which also calm inflammation, to go about daily life.
Researchers say some patients would deem the risk acceptable, but they should be given the choice, the BBC reports.
A study, published in the Lancet, showed the drugs posed even greater risks for smokers and the overweight.
The risks have been reported before, but a team of researchers at the University of Oxford analysed the issue in unprecedented detail in order to help patients make an informed choice.
The group investigated more than 353,000 patient records from 639 separate clinical trials to assess the impact of non-steroidal anti-inflammatory drugs.
They looked at high-dose prescriptions levels, rather than over-the-counter pain relief, of 150mg diclofenac or 2400mg ibuprofen each day.
They showed that for every 1000 people taking the drugs there would be three additional heart attacks, four more cases of heart failure and one death as well cases of stomach bleeding - every year as a result of taking the drugs.
So the number of heart attacks would increase from eight per 1000 people per year normally, to 11 per 1000 people per year with the drugs.
Lead researcher Professor Colin Baigent said this should not concern people taking a short course of these drugs, for example for headaches.
However, he warned that those already at risk of heart problems would be at even greater risk as a result of the high-dose drugs.
High blood pressure, cholesterol and smoking all increase the risk of heart problems.