Gout Information

The blood test

In the blood test to measure levels of uric acid, blood is drawn from a vein or capillary. The laboratory then centrifuges the blood to separate the serum from the cells and the uric acid test is performed on the serum.

Preparing for the blood test

Your doctor may ask you to fast for four hours prior to the test. You may also be advised to stop taking any drugs that increase levels of uric acid. These include:

aspirin
caffeine
alcohol
diuretics (water tablets, such as Diamox, Burnex, Edecrin and Lasix)
ascorbic acid (vitamin C tablets)
diazoxide
ethambutol
methyldopa
phenothiazines
epinephrine
cisplatin
vincristine

Drugs that can decrease uric acid measurements should also, ideally, be temporarily discontinued prior to the test, with the backing of your doctor. These include:

high-dose aspirin
allopurinol
clofibrate
corticosteroids
azathioprine
guafenesin
probenecid
warfarin

The laboratory should be notified if you have recently undergone X-ray testing using contrast dyes. These chemicals increase uric acid levels in urine and decrease them in the blood.