The Downside of Antibiotics for UTI

June 2, 2022

Written by Clay Smith

Spoon Feed
Antibiotics have a good and bad side for women with uncomplicated cystitis. Use of trimethoprim-sulfamethoxazole (TMP-SMX) and other antibiotics, when compared to nitrofurantoin, had higher risk of adverse events.

Why does this matter?
For uncomplicated cystitis, TMP-SMX and nitrofurantoin are firstline agents. Are they the same with regard to adverse events? What if a non-firstline agent (such as a broader spectrum drug) is used?

Antibiotics – good and bad…
This was a large market database, including all 50 U.S. states plus D.C., with almost 1.2 million non-pregnant women from 18-44 years of age with uncomplicated UTI who were treated with an antibiotic. Risk of adverse events, such as hypersensitivity reaction, acute renal failure, skin rash, urticaria, abdominal pain, and nausea/vomiting was 20-160% higher with TMP-SMX over nitrofurantoin. When another drug was used firstline (excluding TMP-SMX that we already discussed) compared to nitrofurantoin, the risk of adverse events was also higher and events associated with disturbing the microbiome were also much higher, such as: diarrhea, C. difficile colitis, vaginitis/vulvovaginal candidiasis, and pneumonia. Reducing the duration of therapy helped reduce such microbiome-related adverse events. Nitrofurantoin appears to be the best choice for uncomplicated cystitis. Just remember, nitrofurantoin should not be used for complicated UTI, including pyelonephritis, as it has poor tissue penetration.

Source
Association of Adverse Events With Antibiotic Treatment for Urinary Tract Infection. Clin Infect Dis. 2022 Apr 28;74(8):1408-1418. doi: 10.1093/cid/ciab637.