Allopurinol

Allopurinol (brand name Uricto Zyloric,^[1] Caplenal, and Zyloprim^[2]) is a medication made for treating high blood uric acid. It does this by making the level of uric acid in the blood lower.^[3] When there is more uric acid in the body than at normal times, it is called hyperuricemia.

Allopurinol was approved for medical use in the United States in 1966.^[4] It was the 39th most commonly prescribed medication in the country in 2022. In that year, more than 15 million prescriptions were filled (sold) in America.^[5][6] It is on the World Health Organization's List of Essential Medicines.^[7] Allopurinol is available as a generic medication.^[4]

The FDA found that allopurinol can be found in the breast milk of a mother taking the drug.^[2] They also recommend to ask if it is safe and necessary to take it and about risk to the unborn child or a baby taking breast milk. In the United Kingdom, the pregnancy guidelines recommend that it is not usually taken while pregnant and that information on breastfeeding should be asked for from the doctor or midwife^[8] before continuing.

It is prescribed for preventing gout,^[9] preventing specific types of kidney stones, and for the high uric acid levels occurring with chemotherapy.^[10][4]

It is taken orally (by mouth) or intravenously (injected into a vein). In some cases it is replaced with an alternative. Allopurinol is used alone as a drug to treat in these uses, or other conditions. In some cases it is used with other drugs in a combination therapy. How it is used and if there is risks for using it depends on the regular function as well as individual needs of the patient.