By Pat Anson, Editor

Taking prescription strength non-steroidal anti-inflammatory drugs (NSAIDs) raises the risk of a heart attack as soon as the first week of use, according to a large new study published in The BMJ.

An international teams of researchers analyzed data from eight studies involving nearly 450,000 patients in Canada, Finland and Germany -- 61,460 of whom had a heart attack. They found that taking any dose of NSAIDs for one week, one month, or more than a month was associated with an increased risk of myocardial infarction. Researchers estimated that the overall risk of a heart attack was about 20 to 50% higher when using NSAIDs.

"Given that the onset of risk of acute myocardial infarction occurred in the first week and appeared greatest in the first month of treatment with higher doses, prescribers should consider weighing the risks and benefits of NSAIDs before instituting treatment, particularly for higher doses," wrote lead author Michèle Bally, PhD, an epidemiologist at the University of Montreal Hospital Research Center.

The NSAIDs of particular interest to the researchers were ibuprofen, diclofenac and naproxen, as well as the COX-2 inhibitors celecoxib and rofecoxib. COX-2 inhibitors work differently than traditional NSAIDs, by targeting an enzyme responsible for pain and inflammation.

“All NSAIDs, including naproxen, were found to be associated with an increased risk of acute myocardial infarction. Risk of myocardial infarction with celecoxib was comparable to that of traditional NSAIDS and was lower than for rofecoxib. Risk was greatest during the first month of NSAID use and with higher doses,” Bally wrote.

Several previous studies have also found that NSAIDs and COX- 2 inhibitors raise the risk of a heart attack, but the exact cause is unknown. Researchers at the University of California Davis reported last year that NSAIDs impaired the activity of cardiac cells in rodents.  

NSAIDs are widely used to treat everything from fever and headache to low back pain and arthritis. They are in so many different pain relieving products, including over-the-counter cold and flu products, that health officials believe many consumers may not be aware how often they use NSAIDs. 

In 2015, the U.S. Food and Drug Administration ordered that stronger warning labels be put on NSAIDs to indicate they increase the risk of a heart attack or stroke. The warning does not apply to aspirin.

“There is no period of use shown to be without risk,” said Judy Racoosin, MD, deputy director of FDA’s Division of Anesthesia, Analgesia, and Addiction Products. “Everyone may be at risk – even people without an underlying risk for cardiovascular disease.”

The BMJ study was published the day after Canada released new guidelines that recommend NSAIDs as an alternative to opioid pain medication. The Canadian guideline makes no mention of the health risks associated with NSAIDs, but focuses on their “cost effectiveness.”

“NSAID-based treatment may have lower mean costs and higher effectiveness relative to opioids,” the new guideline states. “Naproxen-based regimens in particular may be more cost effective compared to opioids and other NSAIDs, such as ibuprofen and celecoxib.”

Opioid guidelines released last year by the U.S. Centers for Disease Control and Prevention, which the Canadian guideline was modeled after, also recommend NSAIDs as an alternative to opioids, but acknowledge the medications “do have risks, including gastrointestinal bleeding or perforation as well as renal and cardiovascular risks.”

Despite those risks, the CDC cited the low cost of NSAIDs and other non-opioid treatments as an “important consideration” for doctors.

“Many pain treatments, including acetaminophen, NSAIDs, tricyclic antidepressants, and massage therapy, are associated with lower mean and median annual costs compared with opioid therapy,” the CDC guideline states.