Allopurinol is primarily used for the long-term treatment and prevention of gout by lowering uric acid levels in the blood, which helps stop gout attacks and prevent joint damage[1]. In addition to managing gout, allopurinol may be prescribed to lower high uric acid levels associated with certain types of cancer treatments, as some therapies can cause a buildup of uric acid[3]. It is also used in patients with recurrent kidney stones composed of calcium oxalate when uric acid levels are high[5].
By consistently reducing uric acid in the bloodstream, allopurinol prevents the formation of urate crystals around joints and in the kidneys, decreasing both the frequency of gout attacks and the risk of complications such as joint damage and kidney stones[1]. It does not treat acute gout attacks directly but is used to prevent future flare-ups and should be continued even if attacks initially worsen during the first months of treatment[1].
Allopurinol is generally taken as a daily tablet and is available only by prescription[3]. Doctors may also recommend it for patients who experience high uric acid during leukemia, lymphoma, or other malignancies due to cell breakdown from cancer therapy[5].