# Allergies to antibiotics among US women with uncomplicated urinary tract infection

## TL;DR

This study found that about a quarter of US women with uncomplicated UTIs reported antibiotic allergies, with allergies to commonly prescribed antibiotics like SXT being most common.

## Contribution

The study provides new data on the frequency and patterns of self-reported antibiotic allergies in women with uncomplicated UTIs in the US.

## Key findings

- Most participants (69.3%) reported no antibiotic allergies, while 24.0% reported one allergy and 6.7% reported two or more.
- SXT was the most commonly prescribed antibiotic and also the most frequently reported allergy.
- Participants with recurrent UTIs or those prescribed multiple antibiotics had higher rates of antibiotic allergies.

## Abstract

Uncomplicated urinary tract infections (uUTI) are generally treated empirically with antibiotics. However, antibiotic allergies limit the available oral treatment options for some patients. We assessed the proportion of self-reported antibiotic allergies among US women with uUTI. We performed a cross-sectional survey of US women (≥18 years) with a self-reported uUTI in the previous 60 days and an oral antibiotic prescription. Participants completed an online questionnaire about their most recent uUTI episode. Descriptive self-reported allergy data were stratified into subgroups by whether the participant had recurrent UTI (≥2 uUTIs in the past 6 months or ≥3 uUTIs in past 12 months, including the index episode), the number of different antibiotics given for the index episode (1, 2, ≥3), and whether the treatment was clinically aligned according to Infectious Diseases Society of America uUTI guidelines. Overall, 375 participants completed the questionnaire. The most commonly prescribed antibiotics were trimethoprim-sulfamethoxazole (SXT; 38.7%), ciprofloxacin (22.7%), and nitrofurantoin (18.9%). Most participants (62.7%) received only 1 antibiotic for their uUTI, and most (56.5%) were classified as having a non-recurrent uUTI. No antibiotic allergies were reported for most participants (69.3%), with 24.0% reporting 1 antibiotic allergy and 6.7% reporting ≥2 antibiotic allergies. Allergies to ≥2 antibiotic types were more common among participants classified as having recurrent uUTI, or who used multiple antibiotics to treat their uUTI. The most common allergy was to SXT (15.7%), followed by amoxicillin-clavulanate (8.3%) and ciprofloxacin (5.3%). Similar allergy trends were seen across subgroups, except higher rates of ciprofloxacin allergy were seen in participants given multiple antibiotics. Antibiotic allergies were relatively frequent in this uUTI cohort and the most common allergy was to SXT, which was the most prescribed antibiotic. Allergies to antibiotics reduce the available treatment options for uUTI in some patients.