Allopurinol

Brand names

• Alloprin
• Apo-Allopurinol
• Lopurin
• Novo-Purol
• Purinol
• Riva-Purinol
• Zurinol
• Zyloprim

Usage

To treat chronic gout or excessive uric acid buildup caused by kidney disorders, cancer, or the use of chemotherapy medicaments for cancer. Also prescribed to prevent recurrence of uric acid kidney stones. Allopurinol should not be used for treating acute gout attacks in progress.

How it works

Allopurinol blocks the enzyme xanthine oxidase, which is required for the production of uric acid, thus reducing blood levels of uric acid.

Side effects

Serious

Anemia or other blood or bone marrow disorders that may produce fatigue, bleeding, or bruising; yellowish tinge to eyes or skin (signifying hepatitis or liver damage); severe skin reactions (marked by rashes, skin ulcers, hives, intense itching); chest tightness; weakness. Seek medical advice right away if such symptoms arise.

Common

Mild rash, drowsiness, nausea, diarrhea. The frequency of gout attacks may increase during the first weeks of use.

Less common

Headache, abdominal pain, boils on face, chills or fever, vomiting, hair loss.

Possible interactions

Other medicaments:

Allopurinol may increase the effects of:

• azathioprine (Imuran) and mercaptopurine (Purinethol), making dose decreases necessary.
• oral anticoagulants such as warfarin (Coumadin). INR should be checked more often.
• theophylline (aminophylline, Elixophyllin, Theo-Dur, etc.).

Allopurinol taken concurrently with:

• ampicillin, amoxicillin (and perhaps other penicillins) may increase the incidence of skin rash.
• antacids containing aluminum will decrease the therapeutic effect of allopurinol.
• captopril (Capoten) or other ACE inhibitors can increase the likelihood of allergic reactions.
• chlorpropamide (Diabinese)) can cause hypoglycemia.
• cyclophosphamide (Cytoxan, Neosar) may result in cyclophosphamide toxicity.
• cyclosporine (Sandimmune) can cause cyclosporine toxicity.
• iron salts may lead to excess liver iron. Avoid combining.
• mercaptopurine (Purinethol) increases toxicity risk.
• probenecid (Benemid, others) may increase probenecid levels.
• tamoxifen (Nolvadex) may result in increased allopurinol levels and increased risk of liver toxicity.
• thiazide diuretics may decrease kidney function.
• theophylline (Theo-Dur, etc.) may cause toxic theophylline levels.
• vidarabine (Vira-A) may increase risk of neurotoxicity.

Foods:

Talk to your doctor about a low-purine diet (such as avoiding liver, lentils, anchovies, etc.). A low protein diet may increase toxicity risk if dose isn't decreased.

Herbal medicines or minerals:

Acerola is high in vitamin C. Inosine, like acerola, may increase uric acid levels. Aspen should be avoided in gout. Lipase may worsen gout. Goutweed (aegopodium podagraria) does not have enough data to assess effectiveness.

Alcohol:

Alcohol can worsen gout. Best to avoid it.

Discontinuation:

If you have a seizure disorder, this medicine dose should be slowly decreased and then stopped.

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