New research by doctors in Tokyo supports the practice of prescribing antihyperuricemic drugs to patients with recurrent gouty arthritis to lower their serum urate concentrations, showing that keeping urate levels at a minimum of 6 milligrams per deciliter results in prevention of future gouty attacks.Acute gouty arthritis is associated with hyperuricemia, which reflects excess uric acid that increases the risk of developing painful monosodium urate crystals in joints, connective tissue, and other organs. For years doctors have prescribed antihyperuricemic drugs, such as allopurinol and uricosuric agents to treat patients with gout. But few studies have suggested a target serum urate level to prevent recurrent attacks.
So, doctors at Tokyo Women’s Medical University in Japan followed 267 patients starting one year after their initial diagnosis of gout to see if persistent reduction of serum urate concentrations, through the use of medications, would reduce the incidence of gouty attacks. Among these 267 patients, 35 did not receive antihyperuricemia medication because they were considered low-risk.
Drug therapy was started in high risk patients at the lowest doses to minimize gouty attacks—one of the initial side-effects of taking the drugs. Patients were requested to visit the clinic at the hospital monthly where doctors measured their serum urate concentrations and recorded the occurrence of any gouty attacks. Data was collected for up to 3 years after their initial visit to the clinic. But the study did not officially begin until one year after the patients’ first visit to the clinic, because the drugs are often the cause of gouty attacks during the first few months of use.
Of the 267 patients in the study, 91 experienced at least one gouty attack a year or more after their initial visit to the clinic. The patients who were on medication and still developed gout had a higher average serum urate concentration than patients taking the drugs that did not experience a gouty attack. During the trial period, the average serum urate levels of patients with recurrent gouty attacks were 7.20 milligrams per deciliter. Those with no gouty attacks had average urate levels of 6.46. The researchers stated there was no association between type of medication and the incidence of gouty attacks.
“In this study, antihyperuricemic drugs effectively reduced the risk of recurrent gouty attacks during the observation period by significantly reducing the average serum urate concentration,” reported the researchers.
This was particularly evident in patients considered low risk at the beginning of the study, since they were not prescribed medication. Over 3 years they eventually experienced more frequent gouty attacks than the patients in the medication group.
“This result demonstrated that maintaining serum urate at subsaturating levels was effective in gout patients and that antihyperuricemic drugs were clearly useful for this purpose,” the researchers reported.
They also observed that the lower the serum urate level, the lower the incidence of gout. Based on measurements from patients taking medications who did not experience recurrent gout, the researcher recommend a target of less than or equal to 6.0 milligrams per deciliter as an aim for antihyperuricemic therapy.
