Results from the data analyses indicated that participants who started to take diclofenac during the trial period were at an increased risk of all major cardiovascular events, including atrial fibrillation, ischeamic stroke, heart failure, myocardial infarction, and cardiac death, irrespective of age and sex.
They examined the cardiovascular risks of starting diclofenac compared with no NSAIDS, starting other traditional NSAIDs and paracetamol.
Now a groundbreaking study of more than six million people, the biggest of its kind, has linked them to "major cardiovascular events".
Diclofenac is found in Voltaren, Arthrotec, and more treatments. Diclofenac is a traditional NSAID that has similar selectivity for cyclo-oxygenase-2 (COX 2) as COX 2 inhibitors, but the cardiovascular risks of diclofenac in comparison with other traditional NSAIDs have not been investigated through a randomized controlled trial.
The researchers concluded that diclofenac should not be available over the counter, but should have to be prescribed by a doctor, with warning labels on the packaging to ensure patients are aware of the risk before they begin to take the drug.
While NSAIDs are commonly recommended to treat inflammatory conditions, headaches, and fever, the drugs are thought to have some cardiovascular risks.More news: DOJ to announce charges against North Koreans for Sony hack, Wannacry attack
In the new study, Morten Schmidt at Aarhus University Hospital in Denmark examined the cardiovascular risks of starting diclofenac compared with no non-steroidal anti-inflammatory drugs (NSAIDS) - other drugs in diclofenac's category.
They also increased by 20 percent compared to those on ibuprofen or paracetamol, and 30 percent compared to those using naproxen. But the authors of a new study argue that diclofenac shouldn't be allowed as an over-the-counter drug, or at the very least, should be accompanied by appropriate warnings.
Dr Schmidt said: "Treatment of pain and inflammation with NSAIDs may be worthwhile for some patients to improve quality of life despite potential side effects".
"While NSAID use previously was considered risk-neutral in short treatment periods and low doses, the risks were apparent even within 30 days and also for low doses of diclofenac". The researchers add that while the relative risk for heart issues was seen to increase, the absolute risk for patients stayed low.
While the researchers did acknowledge this was an observational study, they also noted the sample sizes they used were larger than what has been used with previous research on the same subject.
The researchers believe its high time that the potential health risks of the drug are recognised and that its usage is reduced, including not making it available over the counter.