Allopurinol or febuxostat for chronic gout?

AS A PHARMACIST, you’ll get questions about managing chronic gout due to continued debate over whether to aim for a target uric acid level. We know to consider a chronic medication to lower uric acid when gout causes problems such as tophi or 2 or more acute gout flares/year. But there’s not much evidence on the best way to titrate medications. Some “treat to target” based on limited data that keeping uric acid below 6 mg/dL reduces flares or tophi. Others adjust medications if patients have flares. That’s because patients may have high uric acid, but not experience a flare or have a flare despite a level below 6 mg/dL.

          Consider a blended approach to medication titration, that weighs uric acid levels AND history of flares. When a chronic gout medication is needed, stick with allopurinol (Zyloric). Typically begin treatment 1 or 2 weeks AFTER flare resolution.

Start with allopurinol (Zyloric) 100 mg/day or 50 mg/day if CrCl is below 60 mL/min to reduce hypersensitivity risk. Check labs and increase the dose every 2 to 4 weeks. Generally, aim to get uric acid below 6 mg/dL. Once patients are stable on allopurinol, monitor serum uric acid about annually. But don’t feel compelled to adjust the dose if patients don’t report flares even if their uric acid level is up. Check adherence to allopurinol before making dose changes. If needed, increase up to 800 mg/day in normal renal function, or 300 mg/day or even higher in kidney disease. Advise patients to stop allopurinol and call for a new rash or itching especially within 2 months of a dose increase.

Save other medications for when patients can’t take allopurinol. Lean away from febuxostat (Xanthistop) due to its cardiovascular risk or probenecid due to many interactions and risk of kidney stones. Products with lesinurad (Zurampic) are off the market due to low demand. Give an NSAID, low-dose colchicine, or oral steroid when starting a uric acid-lowering medication since this can trigger a flare. Educate patients to continue chronic gout medications during a flare. For further information, see topic on Comparison of gout therapies.

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