Dec. 21 (UPI) -- Drugs long thought to soothe long-term knee pain may not actually work, a study says.
The research, published Friday in JAMA, come from 47 trials over the course of a year. The work found that only two drugs had any level of significant effectiveness, even though those drugs were only mildly successful.
"This is the first meta-analysis in osteoarthritis (OA) that takes into account only long-term (defined as at least 12-month duration) clinical trials," Lucio Rovati, a researcher at Department of Medicine and Surgery and study author, told UPI in an email interview.
"Analysis of long-term data is particularly important because OA (knee OA in our case, i.e. the most common form and joint localization of OA) is a chronic and progressive disease, but most medications are studied mainly for their short-term effects, i.e. mostly up to 3-6 months only. This creates troubles when physicians have to perform chronic management of their patients," he said.
The NSAID celecoxib and prescription-grade glucosamine sulfate were the only drugs that showed any positive long-term response for knee pain.
"Safety concerns remain that discourage use of this and any other NSAID beyond short-term use," Rovati said.
Along with glucosamine sulfate, chondroitin sulfate and strontium ranelate did improve joint structure in participants, but neither of the last two helped improve overall knee pain symptoms, according to Rovati. He adds that strontium ranelate is only available in Europe and under restricted use because of safety concerns.
Knee pain often originates from arthritis. According to the Centers for Disease Control and Prevention, 54 million Americans have arthritis.
"None of the medications was significantly associated with long-term improvement in pain, except celecoxib and prescription-grade glucosamine sulfate," Rovati said.
To help reduce inflammation without drugs, Rovati recommends using patella tape or heat or cold to relieve pain, or losing weight to take pressure off the knee.
"Physicians should be aware that the clinical trial evidence to support long-term pharmacological management of knee OA is scarce," Rovati said. "None of the medications was significantly associated with long-term improvement in pain."