The Benefits of Gout
Treatment for gout, a painful arthritic condition, involves lowering serum urate levels, which are always very high in gout patients. The irony is that high serum urate levels have been demonstrated as lowering the risk for Parkinson's disease (PD). Two recent studies may have significance in identifying how gout medication might increase the risk of developing PD. One study compares the drug febuxostat, already approved for use in Europe, with the more common allopurinol, for safety and effectiveness. Another study looked at the connection between PD and gout in the elderly. Both studies were published in the November 2008 issue of Arthritis Care & Research.
Allopurinol has been around for decades but can sometimes cause dangerous rashes. Those with less than optimal kidney function must take smaller, less effective doses. On the other hand, clinical trials proved that febuxostat lowers uric acid levels without any need to adjust for impaired kidney function.
The APEX (Allopurinol and Placebo-Controlled, Efficacy Study of Febuxostat) trial was undertaken to compare febuxostat, allopurinol, and a placebo in patients with high uric acid levels (uricemia) and gout. Some of the participants had impaired kidney function. The 28 week trial was led by H. Ralph Schumacher of the University of Pennsylvania and involved 1,072 participants with urate levels of 8 mg/dl and above, plus gout, some with impaired renal function. Patients were given one of three dosage levels of febuxostat, or they were given allopurinol or the placebo. Those with impaired renal function were given half the regular dose of allopurinol.
Many more patients in the febuxostat group managed to lower their serum urate levels below 6 mg/dl by the last three months of participation in the study. Half of those with impaired renal function in the febuxostat group achieved this level, while none of the patients with renal function issues on the lowest dose of allopurinol achieved such a reduction.
Those in the febuxostat groups had more flare-ups than the other groups during the first 8 weeks of the trial. The researchers posit that a sudden reduction of urate levels might cause uric acid crystals to mobilize. Side effects were mostly mild or moderate in all the groups, occurring at a similar rate across the board. Febuxostat seemed to produce the desired effect at the lowest dosage level without need for dosage adjustment in patients with impaired renal function.
In the second study, led by Hyon Choi of the Arthritis Research Centre of Canada in Vancouver, gout patients were divided according to those who received treatment compared to those who did not. In this study, 11, 258 gout patients aged 65 and older and 56,199 healthy subjects in the same age bracket were divided into groups, with the gout patients separated according to those undergoing treatment with at least one medication (72%) and those not receiving any anti-gout medication for the duration of the study, from 1991-2004. Other data analyzed included concurrent conditions and medication use, for instance diuretics and nonsteroidal anti-inflammatory drugs (NSAIDs) which have been linked with a risk for gout and PD.
During the 8 year follow-up, researchers discovered 1,182 participants had developed PD. The gout group had a 30% decrease in the risk for PD, which proved to be independent of other factors. "These findings lend further support to the purported protective role of uric acid against PD," the authors say, though they comment that lowering urate levels more than is necessary may lead to the development of PD in gout patients.