Allopurinol (Zyloprim)

Allopurinol is a medication that helps prevent attacks of gout.

Allopurinol reduces the body’s production of uric acid by inhibiting an enzyme called xanthine oxidase. This enzyme is involved in the chemical process that produces uric acid in the body. Buildups of excess uric acid can lead to gout and kidney stones.

Allopurinol belongs to a class of medications called xanthine oxidase inhibitors.

Taking Allopurinol

Allopurinol is available in 100 and 300 mg oral tablets. The usual dose for Allopurinol is between 50 to 800 mg every day, depending on a doctor’s prescription.

It takes time for this medicine to work, and patients may have flares of gout when they start. It is important for people starting Allopurinol to be patient and continue taking the medication as prescribed by their doctor.

If gout flares while taking Allopurinol, patients should see their doctor so that the flare can be treated with a different medicine.

Important Tests and Risks




Watch Canadian rheumatologist Dr. Andy Thompson introduce Allopurinol in this short video:


Allopurinol Quick Reference Guide