Trade Name(s):
Available
Dose
Indications
Long-term therapy of gout, prevention of recurrent flares, prevention of uric acid-related kidney stones
Side Effects
Though rare, the most significant reaction is the allopurinol hypersensitivity syndrome, characterized by a rash and fever, sometimes accompanied by low blood counts, kidney and liver function abnormalities. Other more common side effects include nausea, diarrhea, abdominal pain, headache, a metallic taste in the mouth, and drowsiness. Uncommonly, prolonged use of allopurinol has been associated with an increased risk for cataracts.
Monitoring
Uric acid levels should be obtained weekly to monthly while adjusting the dose of the medication. Blood counts, kidney and liver function studies can be obtained annually or if signs of hypersensitivity develop.
Important Points to Know
This medication’s role is to reduce uric acid levels and stabilize the course of gout, preventing acute flares. During an acute flare, the dose of the medication should not be changed, as allopurinol does not have a direct effect on inflammation, and shifts in the uric acid levels tend to worsen symptoms. Do not discontinue this drug without notifying the provider. Allopurinol may interact with other medications such as warfarin (coumadin) and azathioprine (Imuran), notify your provider if you are taking either of these medications. Rashes are more common when allopurinol is taken with the antibiotic ampicillin.