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A 33-year-old male asked:

I'm on bactrim (tmp/smx). i've heard and read that it can contribute to kidney stones if you don't drink enough fluids. i worry that i'm not drinking enough but my urine is pale yellow to clear. i try to drink at least 2 l but sometimes i forget?

2 doctor answers2 doctors weighed in
Dr. Samuel Galima
Family Medicine 9 years experience
Trimethoprim-sulfamethoxazole (Bactrim DS) does not have kidney stones listed as a side effect or adverse effect. There are other verified side effects, please review the manufacturer insert that should be included with the prescription from the pharmacy. Adequate hydration is always best practice regardless.
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Hiep Le
Dr. Hiep Leanswered
Nephrology and Dialysis 44 years experience
Crystalluria (kidney stone may develop because of this) is a moderate side effect of Bactrim but the incidence is not known and I would say it is extremely rare by my personal experience. Because this side effect is preventable by drinking fluid well when taking this antibiotic so this practice has been recommended. If you drink adequately, you should be fine, do not worry much.
Created for people with ongoing healthcare needs but benefits everyone.
Last updated Jul 18, 2022


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