By Pat Anson, Editor

The most widely used painkiller in the world should be banned as an over-the-counter drug because it significantly raises the risk of cardiovascular problems and gastrointestinal bleeding, according to a large new study published in the British Medical Journal (BMJ).

Diclofenac is not well-known in the United States, but it is the most widely used non-steroidal anti-inflammatory drug (NSAID) in the world. It is sold both as a prescription and over-the-counter medication under various brand names such as Voltaren, Cambia, Zorvolex and Solaraze.

Researchers looked at healthcare data from over 6 million people in Denmark from 1996 to 2016 and found that those who used diclofenac were 50 percent more likely to have cardiovascular problems such as atrial fibrillation, heart failure and stroke in the first 30 days compared to those who took nothing. Their risk of gastrointestinal bleeding was also higher.

Out of every 1,000 people who used diclofenac, the study estimated that four additional people would develop a major health problem within a year.

"It is time to acknowledge the potential health risk of diclofenac and to reduce its use. Diclofenac should not be available over the counter, and when prescribed, should be accompanied by an appropriate front package warning about its potential risks," wrote lead author Morten Schmidt, MD, Aarhus University Hospital.

"Treatment of pain and inflammation with NSAIDs may be worthwhile for some patients to improve quality of life despite potential side effects. Considering its cardiovascular and gastrointestinal risks, however, there is little justification to initiate diclofenac treatment before other traditional NSAIDs."

This is not the first time that researchers have warned about the health risks associated with diclofenac and other NSAIDs.

In 2016, researchers at 14 European universities and hospitals, including a number of leading heart specialists, warned that some NSAID’s raise cardiovascular risk and that there is no "solid evidence" the drugs are safe.

Some of the greatest cardiovascular risk comes from a class of NSAIDs known as COX-2 inhibitors. A COX-2 inhibitor called Vioxx was voluntarily pulled from the market by Merck in 2004, but many other COX-2 inhibitors, such as diclofenac, are still widely used for pain relief.   

Another 2016 study published in the BMJ found that use of any NSAID was associated with a 20 percent higher risk of being hospitalized with heart failure. These seven NSAIDs were found to be the riskiest:

• diclofenac
• ibuprofen
• indomethacin
• ketorolac
• naproxen
• nimesulide
• piroxicam

NSAIDs are used to alleviate pain and reduce inflammation, and are found in a wide variety of over-the-counter products – from headache relievers to cold and flu remedies. They are used in so many different products -- such as Advil and Motrin -- that many consumers may not be aware how often they use NSAIDs. 

In 2015, the U.S. Food and Drug Administration ordered warning labels for all NSAIDs to be strengthened to indicate they increase the risk of a fatal heart attack or stroke. The FDA said studies found the risk of serious side effects can occur in the first few weeks of using NSAIDs and could increase the longer people use the drugs. The revised warning does not apply to aspirin.

The European Society of Cardiology recommends limited use of NSAIDs by patients who are at increased risk of heart failure. Those already diagnosed with heart failure should refrain from using NSAIDs completely.