Arthritis Q&A by Dr. Shiel
I have read in your pages that Aspirin increases uric acid to rise in the blood, and that a rise in uric acid in the blood is the cause of Gout. As I take 75 mg of aspirin every day, will this cause Gout?
Medical Author: William C. Shiel Jr., MD, FACP, FACR
Your question brings up a number of important issues about Gout.
First, Gout is medical condition characterized by abnormally elevated levels of uric acid in the blood, recurring attacks of joint inflammation (arthritis), deposits of hard lumps of uric acid in and around the joints, and decreased kidney function and kidney stones. While Gout is often associated with an abnormally elevated blood uric acid level, it need not be. That is, the medical condition of Gout can exist in an individual, with or without an elevated uric acid level in that individual. This even holds true for an acute attack of gouty arthritis! So, it is important to understand that it may not necessarily be the level of the uric acid that brings on an acute attack of gout. Frequently, it is a rapid change of uric acid, either up or down, that seems to precipitate an acute attack.
Second, you are correct that small doses of aspirin can elevate the uric acid level. This occurs because aspirin in low doses can impair the excretion of uric acid from the kidneys. The change typically would be only noted when aspirin was taken in the usual over-the-counter doses--that is two 325 mg tablets every four hours. The extremely low dose aspirin 75-81 mg per day, given for example for heart attack or stroke prevention, should not significantly alter the uric acid level. Furthermore, even the higher doses mentioned should only precipitate a Gout attack in a person with Gout, that is, someone at risk for an attack, not in a normal individual.
Finally, it is also of interest to note that there is a very different effect of aspirin on the blood level of uric acid when it is taken at very high doses, such as those prescribed by doctors for treating serious forms of inflammatory arthritis (like rheumatoid arthritis). In these very high doses, aspirin actually blocks reabsorption of uric acid by the kidneys, causing uric acid to be dumped out of the body in the urine and lowering the blood level of uric acid.
Because of the effects of moderate- and high-dose aspirin that can alter the blood level of uric acid, aspirin is generally avoided by persons with a known Gout condition.
Thank you for your question.
Last Editorial Review: 12/14/2006