WEDNESDAY, Feb. 21, 2018 (HealthDay News) -- A malaria drug that's also shown effectiveness against rheumatoid arthritis pain has failed to help people with the more common form of arthritis, new research shows.
The drug is called Plaquenil (hydroxychloroquine), explained one expert who wasn't connected to the new study.
"Plaquenil was first used to treat malaria but was later found to also have beneficial effects in patients with inflammatory arthritis such as rheumatoid and lupus," said Dr. Steven Beldner. He directs the New York Hand and Wrist Center at Lenox Hill Hospital in New York City.
"It is believed that it modulates some of the immune cells to reduce the body's attack on joints," Beldner added.
"There have been debates among physicians about whether [the drug] was effective for the treatment of osteoarthritis, which is not an autoimmune condition," he noted.
Osteoarthritis is the most common form of arthritic joint pain.
According to the researchers behind the new study, hand osteoarthritis affects up to 31 percent of people over 70 and up to 15 percent of those older than 60. The pain can be debilitating and there are few effective treatments.
Plaquenil has been used as an "off-label" treatment -- meaning it's approved for uses other than to treat osteoarthritic hand pain -- but there's been little evidence about its effectiveness.
This British study included 248 patients with hand osteoarthritis. They took either Plaquenil or a placebo for a year while receiving usual care.
The result: The drug "was no more effective than placebo for pain relief in patients with moderate to severe hand pain," the study authors concluded. The research was led by Sarah Kingsbury, of the Leeds Institute of Rheumatic and Musculoskeletal Medicine in Leeds, England.
The researchers said Plaquenil may not be effective in these patients because much of their hand pain may be due to tendon problems rather than arthritis.
Beldner believes the findings may lay to rest the debate over this drug's usefulness in osteoarthritis.
"This well-designed recent study" suggests that Plaquenil "should not be used for osteoarthritis," he said.
The study was funded by Arthritis Research UK and published Feb. 19 in the Annals of Internal Medicine.
The U.S. Centers for Disease Control and Prevention has more on osteoarthritis.