Allopurinol reduces the production of uric acid in your body. Uric acid buildup can lead to gout or kidney stones.

Allopurinol is used to treat gout or kidney stones, and to decrease levels of uric acid in people who are receiving cancer treatment.

Allopurinol may also be used for purposes not listed in this medication guide.

Do not use this medication if you have ever had a serious allergic reaction to allopurinol. Stop taking the medicine and call your doctor at once if you have any signs of skin rash, no matter how mild.

Take each dose with a full glass of water. To reduce your risk of kidney stones forming, drink 8 to 10 full glasses of fluid every day, unless your doctor tells you otherwise.

Allopurinol can lower blood cells that help your body fight infections. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Your blood may need to be tested often. Visit your doctor regularly.

Avoid drinking alcohol. It can make your condition worse.

Allopurinol may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

You should not take allopurinol if you are allergic to it.

To make sure you can safely take allopurinol, tell your doctor if you have any of these other conditions:

• kidney disease;

• liver disease;

• diabetes;

• congestive heart failure;

• high blood pressure; or

• if you are receiving any chemotherapy.

FDA pregnancy category C. It is not known whether allopurinol will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Allopurinol can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.