Millions of people who take widely prescribed anti-inflammatory drugs like naproxen and ibuprofen to ease joint pain may unintentionally increase swelling and discomfort in their knees over time, a new study suggests.
The study focused on people with moderate to severe knee osteoarthritis, a condition that typically develops with advanced age as wear and tear on the body erodes cartilage in the joint and makes movement painful. Scientists studied 277 people who took nonsteroidal anti-inflammatory drugs (NSAIDs) for at least one year to manage their pain and a control group of 793 people who didn’t use these medicines.
At the start of the study, all of the participants had detailed MRI scans of their knees. People using NSAIDs had worse cartilage quality and joint inflammation than individuals who weren’t taking these drugs, according to preliminary results of research to be presented at the annual meeting of the Radiological Society of North America.
There was no long-term benefit to taking NSAIDs based on subsequent scans. After four years, cartilage quality and joint inflammation got even worse for people in the NSAID group, according to the preview of the study results.
“NSAIDs are frequently used to treat pain, but it is still an open discussion of how NSAID use influences outcomes for osteoarthritis patients,” lead author Johanna Luitjens, MD, of the department of radiology and biomedical imaging at the University of California in San Francisco, said in a statement.
“In this large group of participants, we were able to show that there were no protective mechanisms from NSAIDs in reducing inflammation or slowing down progression of osteoarthritis of the knee joint,” Luitjens said.
While the study wasn’t a controlled experiment designed to prove whether or how NSAIDs might directly cause increased cartilage breakdown and joint inflammation in the knees, there are several possible explanations, Luitjens said.
One possibility is that NSAIDs simply fail to prevent what’s known as synovitis, or swelling and pain in the connective tissue that lines joints like the knee, hip, ankle, and shoulder, Luitjens said. Another potential explanation is that NSAIDs do relieve pain, enabling people to continue with physical activities that increase wear and tear on the knee joint over time.
NSAIDs are a family of medicines that include aspirin, ibuprofen (Motrin, Advil), and naproxen (Naprosyn, Aleve). Many types of NSAIDs are available over-the-counter without a prescription at lower doses, and by prescription for higher doses. They’re commonly used to relieve pain, reduce inflammation, and prevent blood from clotting. Side effects can include upset stomach and bleeding.