Detailed Drug Information:

DRUG CLASS AND MECHANISM: Allopurinol is used to lower blooduric acid levels. Uric acid is a breakdown product of purines in foods.Uric acid forms crystals in the tissues of the body to cause theinflammation of gout. Elevated blood uric acid levels can also causekidney disease and stones. Allopurinol can be used to prevent uric acidkidney stones and to prevent recurrent gouty arthritis attacks.

PREPARATIONS: Tablets: 100mg, 300mg.

STORAGE: Store at 59-77 degrees F, in a sealed, light-resistantcontainer, avoid moisture.

PRESCRIBED FOR: Allopurinol is used to treat patients withmultiple recurrent gout attacks, erosive destructive gouty joint disease,hard lumps of uric acid deposits in tissues (called tophi), gouty kidneydisease, or uric acid stones. Allopurinol is also used to preventelevation of blood uric acid in patients undergoing chemotherapy for thetreatment of certain cancers.

DOSING: Should be taken with food to avoid stomach irritation.Patients should also drink plenty of fluids while taking allopurinol.

DRUG INTERACTIONS: Allopurinol should be avoided by patientswith a prior severe reaction to the drug. Allopurinol can cause a flare-upof gouty arthritis while the blood uric acid level is initially adjusted,therefore, Colchicine is often used simultaneously to prevent these flares. Allopurinol is not started during active inflammation because it can worsen and prolong attacks of acute gouty arthritis. Patients taking simultaneous Purinethol or Imuran require reductions of dosages of these drugs. There is an increased risk of skin rash in patients takingampicillin and amoxicillin (Amoxil). Allopurinol can cause a seriousallergic liver toxicity that can be fatal. Appetite loss and itching canbe signs of liver toxicity. The risk of this reaction increases inpatients with kidney impairment. Patients with kidney impairment requirelower doses. Allopurinol is used in children during treatment of cancersor rare diseases of purine metabolism.

PREGNANCY: Safety in pregnancy has not been established.

NURSING MOTHERS: Allopurinol is excreted in breast milk.

SIDE EFFECTS: The most frequent adverse reaction to allopurinolis skin rash. Allopurinol should be discontinued immediately at the firstappearance of rash, painful urination, blood in the urine, eye irritation,or swelling of the mouth or lips, because these can be a signs ofimpending severe allergic reaction, which can be fatal. Rarely,allopurinol can cause nerve, kidney, and bone marrow damage.