Until Uloric became available last year we didn't have much else we could use to prevent attacks of recurrent gout in patients who could not take allopurinol.
This article originally appeared online at DrPullen.com, part of the HCPLive network
Uloric is a great addition to our war chest of drugs to treat gout. First though, readers may wonder if DrPullen.com has become a blog about drugs. Actually, over the last year or so, there have been a number of new medications that have come to market that are going to play major roles in the way most of us practice medicine and be of real benefit to at least some patients. I plan to use Friday posts for the next few weeks to discuss the role of a few of these new drugs in actual practice.
After last week’s post on Viibryd and now this on Uloric I want to be clear that I am no fan of most newer more expensive alternatives to perfectly good cheap generic medications. I am a big proponent of generic drugs, and I almost always use allopurinol when it is a viable option. Allopurinol remains the mainstay of hyperuricemia therapy. It is a highly effective, inexpensive generic drug that physicians have used for years to lower serum uric acid levels and prevent gout attacks.
The problem is that a small minority of patients will develop an allergic rash to allopurinol. Until Uloric became available last year we didn’t have much else we could use to prevent attacks of recurrent gout in patients who could not take allopurinol. In addition, patients allergic to allopurinol and patients with significant renal dysfunction may not be able to use allopurinol, but can sometimes use Uloric. Just having another option for those select patients who cannot use allopurinol is really a big benefit.
Gout is caused by the precipitation of uric acid crystals in joints, causing an acute inflammatory arthritis of the affected joints. Uric acid is the final breakdown product of the DNA building blocks called purines. Our bodies are constantly breaking down the components of dying cells and making new cells. As the DNA of these cells is metabolized the two purines, guanine and cytosine, go through a series of steps to allow our bodies to get rid of them. In this breakdown of purines into metabolites that the body can excrete in the urine, the enzyme xanthine oxidase facilitates the conversion of xanthine into uric acid. Both allopurinol and Uloric are competitive inhibitors of xanthine oxidase and prevent the conversion of xanthine into uric acid. By reducing the serum concentrations of uric acid the gout attacks can be prevented.
You can find a lot of advice on how to prevent gout by diet. Gout is primarily a disease of the developed world and a result of eating a diet too rich in protein. Demographically this is true, but there is not a lot of data to give us confidence that diet modification will prevent attacks of gout in patients who have already had a prior attack of gout. It is rarely easy to change habits, whether diet, exercise, or anything else, and for a lifelong condition like gout, changing diet enough to prevent gout attacks in patients predisposed to gout. Almost all patients who have recurrent acute gout attacks need medication to prevent further episodes.
Another reason that Uloric may be a better choice for select patients over allopurinol is that Uloric is metabolized by the liver in addition to being excreted by the kidney. This allows safe use of Uloric in patients with reduced renal function. Allopurinol is exclusively excreted in the urine and use in patients with moderate to severe renal dysfunction needs especial caution. Uloric with its dual metabolism can be used in patients with more significant renal disease.
In the unusual patient who continues to have gout attacks despite taking allopurinol, 300 mg daily of Uloric at the higher dose of 80 mg may reduce uric acid levels to a greater degree and be more effective at preventing attacks of gout than allopurinol. Data presented by the manufacturer states that 70% of patients taking Uloric 80 mg daily will achieve uric acid levels <6mg/dl vs. only 40% of patients taking allopurinol 300 mg daily.
I’m not sure how significant this advertised benefit is in patient management. In my experience, it is unusual for patients who can take allopurinol 300 mg daily to continue to have recurrent gout attacks, and so the much bigger issue is allopurinol allergy. I’d first discuss remembering to take the medication before I jumped to the more expensive Uloric in the case of individual treatment failures with allopurinol.
In summary, Uloric gives us an effective treatment for patients with gout who have an allergy to allopurinol or other allopurinol side effects, who have reduced renal function and cannot use allopurinol, or who have failed allopurinol therapy and need the higher efficacy of Uloric a lower serum uric acid level than they can achieve with allopurinol in order to avoid recurrent acute attacks of gout.
Ed Pullen, MD, is a board-certified family physician practicing in Puyallup, WA. He blogs at DrPullen.com—A Medical Blog for the Informed Patient