Nov. 16, 2005 -- A new treatment for gout is at least twice as effective at lowering uric acid levels as the standard drug allopurinol, according to results from the longest and largest trial of such drugs ever conducted.
The drug, febuxostat, will likely be the first new agent available to treat gout in more than 40 years, says researcher Robert L. Wortmann, MD, professor and chairman of the department of rheumatology at the University of Oklahoma in Tulsa.
Exactly when the new drug will be approved is not known, but "personally I am optimistic," he says.
The research was presented at the annual meeting of the American College of Rheumatology in San Diego.
Lowering Uric Acid Is Key to Gout Control
Affecting more than 5 million Americans, gout is a chronic arthritic condition characterized by "flares" of intense pain, redness, inflammation, and warmth in the affected joint. Typically, symptoms begin in the big toe, but gout may strike other joints.
Gout is caused by an accumulation of uric acid crystals in the affected joint(s). As the disease progresses, these flares may become more frequent and patients may develop joint deformity and large deposits of crystals, which can become visible under the skin (called tophi).
Uric acid is found naturally in the body. In gout, there is generally a problem with either too much production of uric acid or problems in getting rid of the uric acid, or both.
"When you have gout, there's too much uric acid in the body," Wortmann explains to WebMD. "Uric acid is like matches, and for some reason, one of these matches strike and you get a hot foot."
"We treat the fire with anti-inflammatory drugs or colchicine right away because if not, more matches will catch and the fire will get worse," he explains. Though "these medications can put out the fire, it doesn't get rid of the matches so they still can strike."
Enter febuxostat and allopurinol. And getting rid of these matches is what febuxostat appears to do more effectively than allopurinol, according to the new study.
Febuxostat Hits Target
In the 28-week study, 1,067 people with gout received either placebo (fake) pills, allopurinol, or one of three doses of febuxostat (80, 120, or 240 milligrams). At all three doses, the new agent was more effective at bringing uric acid levels down than allopurinol and placebo.
By the end of the study, 48% of people who took 80 milligrams of febuxostat a day hit their target uric acid level, as did 65% of those taking 120 milligrams per day and 69% of those taking 240 milligrams per day. By contrast, just 22% of participants taking allpurinol hit their mark, and zero people in the placebo group did. What's more, side effects were equal across all groups.
Like allopurinol, febuxostat would be a maintenance medication for gout.
Works for People Who Can't Tolerate Allpurionol
Febuxostat has a different chemical structure than allpurinol, but it acts on the same enzyme that causes uric acid to rise, Wortmann explains.
"It's more potent than allopurinol, more selective, and it can be used in patients with kidney problems who cannot tolerate allopurinol," Wortmann says.
Though allopurinol has been used for 30 years and is considered to be a safe drug, serious side effects can occur -- especially in patients with kidney problems. These side effects are collectively known as allopurinol hypersensitivity syndrome and include widespread rash, fever, mouth sores, poor kidney function, liver inflammation, and other complications.
"It's an excellent agent for patients who can't tolerate or who have had bad reaction to allopurinol," Wortmann says.