By Pat Anson, Editor
At a time when the U.S. Centers for Disease Control and Prevention is recommending that non-opioid pain relievers such as non-steroidal anti-inflammatory drugs (NSAIDs) be used to treat chronic and acute pain, European researchers are warning about health risks associated with those same over-the-counter pain medications.
In guidelines for primary care physicians released on Tuesday, the CDC said "nonopioid pharmacologic therapy" such as acetaminophen and NSAIDs are "preferred" treatments for chronic pain.
Only briefly do the CDC guidelines even mention that NSAIDs “have been associated with hepatic, gastrointestinal, renal, and cardiovascular risks” and that acetaminophen may cause liver failure. The 52-page guideline instead focus on the risks of addiction and abuse associated with opioids.
But in a major new study published this week in the European Heart Journal, researchers at 14 European universities and hospitals, including a number of leading heart specialists, warn that some NSAID’s raise cardiovascular risk and that there is no "solid evidence" the drugs are safe.
"When doctors issue prescriptions for NSAIDs, they must in each individual case carry out a thorough assessment of the risk of heart complications and bleeding. NSAIDs should only be sold over the counter when it comes with an adequate warning about the associated cardiovascular risks. In general, NSAIDs are not be used in patients who have or are at high-risk of cardiovascular diseases," said co-author Christian Torp-Pedersen, a professor in cardiology at Aalborg University in Denmark.
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 around the world for pain relief.
"It's been well-known for a number of years that newer types of NSAIDs - what are known as COX-2 inhibitors, increase the risk of heart attacks. For this reason, a number of these newer types of NSAIDs have been taken off the market again. We can now see that some of the older NSAID types, particularly Diclofenac, are also associated with an increased risk of heart attack and apparently to the same extent as several of the types that were taken off the market," said Morten Schmidt, MD, a postdoctoral research fellow at Aarhus University in Denmark.
Diclofenac is the most widely used NSAID in the world. It is sold under a number of different brand names, including Cambia, Voltaren and Zorvolex.
A second study of NSAIDs, published this week in the New England Journal of Medicine, found that emergency room admissions can be significantly reduced if doctors stopped the “high-risk prescribing” of NSAIDs.
Researchers enrolled a group of primary care physicians in Scotland in an educational program aimed at reducing the exposure of patients with heart or kidney problems to NSAIDs like ibuprofen and aspirin, especially if the patients were taking anticoagulant drugs like warfarin. The study involved over 33,000 high risk patients.
After 48 weeks, the rate of hospital admissions for gastrointestinal ulcers or bleeding was significantly reduced, as was the rate of admissions for heart failure.
"Our previous work has shown that high-risk prescribing is common and often causes important harm. This new study shows that relatively simple interventions can significantly reduce high-risk prescribing in a lasting way, and are associated with reductions in emergency hospital admission for related complications,” said Professor Bruce Guthrie of the University of Dundee in Scotland.
High-risk prescribing and preventable drug-related complications are major concerns for healthcare providers around the world. Up to 4 per cent of emergency hospital admissions are caused by preventable adverse drug events, and in the United States the avoidable cost of drug-related hospital admissions was estimated at $19.6 billion in 2013.
The majority of drug-related emergency admissions to hospitals are caused by commonly prescribed drugs such as NSAIDs and acetaminophen. Over 50 million people in the U.S. use acetaminophen each week for pain and fever – many not knowing the medication has long been associated with liver injury and allergic reactions such as skin rash. Over 50,000 emergency room visits each year in the U.S. are blamed on acetaminophen overdoses.
A recent study in the British Medical Journal found that acetaminophen was ineffective in treating low back pain and provides little benefit to people with osteoarthritis. And in a survey of over 2,000 pain patients by Pain News Network and the International Pain Foundation, 76 percent said that over-the-counter pain relievers “did not help at all” in relieving their pain.