MedlinePlus Drug Information: Allopurinol

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Other drug names:	A-Am An-Az B C-Ch Ci-Cz D-Dh Di-Dz E F G H I-J K-L M-Mh Mi-Mz N-Nh Ni-Nz O P-Pl Pm-Pz Q-R S-Sn So-Sz T-To Tp-Tz U-V W-Z 0-9

Allopurinol

(al oh pure' i nole)

Brand name(s): Lopurin; Zyloprim

Contents of this page:
Why is this medication prescribed? How should this medicine be used? What special precautions should I follow? What special dietary instructions should I follow?	What should I do if I forget a dose? What side effects can this medication cause? What storage conditions are needed for this medicine? What other information should I know?

Why is this medication prescribed?

Allopurinol is used to treat chronic gout and to keep the body from producing excessive amounts of uric acid, which could lead to or aggravate various medical problems. It is used to prevent gout attacks, not to treat them once they occur.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Allopurinol comes as a tablet to take by mouth. It usually is taken once a day, preferably after a meal. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take allopurinol exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Allopurinol may increase the frequency of gout attacks during the first 6-12 months that you take it, although it will eventually prevent them. Another drug, such as colchicine, may be prescribed to decrease this effect.

What special precautions should I follow?

Before taking allopurinol,

tell your doctor and pharmacist if you are allergic to allopurinol or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially amoxicillin (Amoxil, Trimox), ampicillin (Polycillin, Principen), anticoagulants ('blood thinners'), cancer chemotherapy agents (azathioprine, mercaptopurine, cyclophosphamide), chlorpropamide (Diabinese), co-trimoxazole (Bactrim, Septra), diuretics ('water pills'), medication for high blood pressure, theophylline (Theo-Dur), and vitamins.
tell your doctor if you have or have ever had kidney disease, liver disease, high blood pressure, or diabetes.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking allopurinol, call your doctor.
ask your doctor for advice on drinking alcoholic beverages, as alcohol may reduce the effectiveness of allopurinol.

What special dietary instructions should I follow?

Drink at least eight glasses of water or other fluids each day while taking allopurinol unless directed to do otherwise by your doctor.

Avoid excessive amounts of vitamin C supplements or fruit juice while taking allopurinol. Too much vitamin C in combination with allopurinol may increase your chance of developing kidney stones.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Although side effects from allopurinol are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

upset stomach
vomiting
diarrhea
indigestion
drowsiness

If you experience any of the following symptoms, call your doctor immediately:

skin rash
painful urination
blood in the urine
irritation of the eyes
swelling of the lips or mouth

What storage conditions are needed for this medicine?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to allopurinol.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Last Revised - 01/01/2003

American Society of Health-System Pharmacists, Inc. Disclaimer