Possible food and drug interactions when taking Zyloprim

Consumer Information (PDR)

If Zyloprim is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Zyloprim with the following:

Amoxicillin (Amoxil, Trimox, Wymox)
Ampicillin (Omnipen, Principen)
Azathioprine (Imuran)
Blood thinners such as Coumadin
Cyclosporine (Sandimmune, Neoral)
Drugs for diabetes, such as Diabinese and Orinase
Mercaptopurine (Purinethol)
Probenecid (Benemid, ColBENEMID)
Sulfinpyrazone (Anturane)
Theophylline (Theo-Dur, Slo-Phyllin, and others)
Thiazide diuretics such as HydroDIURIL, Diuril, and others
Vitamin C

Consumer Information (Cerner Multum)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For allopurinol, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to allopurinol. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Although studies on birth defects have not been done in pregnant women, allopurinol has not been reported to cause problems in humans. In one study in mice, large amounts of allopurinol caused birth defects and other unwanted effects. However, allopurinol did not cause birth defects or other problems in rats or rabbits given doses up to 20 times the amount usually given to humans.

Breast-feeding—Allopurinol passes into the breast milk. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children—This medicine has been tested in children and, in effective doses, has not been shown to cause different side effects or problems than it does in adults.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of allopurinol in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking allopurinol, it is especially important that your doctor and pharmacist know if you are taking any of the following:

• Anticoagulants (blood thinners)—Allopurinol may increase the chance of bleeding; changes in the dose of the anticoagulant may be needed, depending on blood test results

• Azathioprine (e.g., Imuran) or
• Mercaptopurine (e.g., Purinethol)—Allopurinol may cause higher blood levels of azathioprine or mercaptopurine, leading to an increased chance of serious side effects

Other medical problems—The presence of other medical problems may affect the use of allopurinol. Make sure you tell your doctor if you have any other medical problems, especially:

• Congestive heart disease or
• Type 2 diabetes mellitus or
• High blood pressure or
• Kidney disease—There is an increased risk of severe allergic reactions or other serious effects; a change in the dose of allopurinol may be needed