Examples

How It Works

Uricosuric agents lower uric acid levels in the body by increasing the elimination of uric acid by the kidneys.

Why It Is Used

Uricosuric agents are used to lower the uric acid level in the blood and to prevent the formation of uric acid crystals in your joints and kidneys. They are also used to reduce the frequency of recurrences of acute gout.

Uricosuric agents are never started during a gout attack, but they should be continued if you are already taking them.

Uricosuric agents are not recommended for people who:

• Have urinary tract stones or a urinary tract obstruction.
• Have hyperuricemia and are undergoing chemotherapy or radiation treatment for cancer.
• Are taking moderate doses of aspirin.
• Have kidney failure or kidney disease.

How Well It Works

Uricosuric agents can lower uric acid levels in people with hyperuricemia and gout. Continuous use of uricosuric agents lowers uric acid levels and reduces both the chance of forming and the size of gritty, chalklike clumps of uric acid crystals (tophi).¹ But up to 25% of people using uricosuric agents to lower uric acid levels do not have adequate results.²

Side Effects

Common, mild side effects include:

• Headache.
• Rash.
• Kidney stone formation (may be avoided by drinking more fluids).
• Stomach problems.

Rare, serious side effects include bone marrow problems.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

• Uricosuric agents should not be started until the symptoms of a gout attack are gone. But if you are already taking these medicines, you should continue to take them, even during an attack.
• Gout attacks may increase at first for some people taking probenecid. To avoid this, doctors may prescribe colchicine or low-dose nonsteroidal anti-inflammatory drugs (NSAIDs), which reduce the inflammation caused by uric acid crystals, to be taken at the same time. After normal uric acid levels have been maintained for 6 to 12 months and no further attacks occur, colchicine or NSAIDs usually do not need to be taken.
• These medicines can be taken with milk or food to reduce the chance of stomach irritation. (They should not be taken with antacids.)
• While taking these medicines, drink more fluids to prevent the risk of kidney stones.

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References

Citations

1. Hellman DB, Stone JH (2005). Arthritis and musculoskeletal disorders. In LM Tierney Jr et al., eds., Current Medical Diagnosis and Treatment, 44th ed., pp. 781–789. New York: McGraw-Hill.
2. Wise C (2007). Crystal-induced joint disease. In DC Dale, DD Federman, eds., Scientific American Medicine, section 15, chap. 9. New York: WebMD.