A Multicenter Prospective Cohort Study of Antibiotics for OnabotulinumtoxinA

Thursday, October 24, 2024

12:22 PM – 12:32 PM EDT

Location: Independence Ballroom E-H (Meeting Level 4)

Objectives: Urinary tract infection (UTI) is the most common complication of intradetrusor onabotulinumtoxinA (BTX-A) injection. Despite this, there are no evidence-based guidelines on antibiotic prophylaxis for the procedure. We performed a prospective cohort study to investigate whether antibiotic prophylaxis decreased UTI rates within six weeks of intradetrusor BTX-A injection.

Methods: This was a prospective, observational multicenter cohort study of female patients receiving intradetrusor BTX-A for idiopathic overactive bladder. We compared patients who received antibiotic prophylaxis (nitrofurantoin 100mg BID for 5 days or trimethoprim-sulfamethoxazole (TMP-SMX) DS BID for 3 days starting on the day of injection) versus those who did not. The primary outcome was symptomatic, culture-proven UTI within six weeks. Composite UTI, defined as culture-proven UTI or empirically treated UTI from outside hospital, was also recorded. To detect a 15% difference in culture-proven UTI rates between groups with 80% power and alpha=0.05, 270 participants (180 in the antibiotic cohort and 90 in the no-antibiotic cohort) were needed. T-tests, Wilcoxon Rank Sum, Chi-square or Fisher’s exact tests were used where appropriate to assess for differences in the study cohorts. Multivariable logistic regression was performed to identify factors associated with UTI post-procedure. Model fit was tested using the Hosmer-Lemeshow goodness-of-fit test and by inspection of residuals, deviance, and leverage. A p-value ≤0.05 was considered statistically significant.

Results: Of 509 patients, 332 were deemed eligible, 289 were enrolled in the study, and 282 ultimately received BTX-A and were included in the analysis. 181 (62.6%) were in the antibiotic cohort and 101 (35.8%) in the no-antibiotic cohort. The overall rate of symptomatic, culture-proven UTI was 12.1%, and there was no statistically significant difference in UTI rate between the antibiotic and no-antibiotic cohort (10.6% versus 14.9%, respectively, p=0.29). Composite UTI rate was 12.2% in the antibiotic cohort versus 19.8% in the no-antibiotic cohort (p=0.087). There was no difference in the primary outcome between nitrofurantoin and TMP-SMX (11.8% v. 5.6%, respectively, p=0.37). On multivariable logistic regression, UTI was associated with older age (aOR 1.07; 95% CI 1.02-1.11; p=0.004), BTX-A dose of 200 units (aOR 4.24; 95% CI 1.45-12.35; p=0.008), and self-catheterization (aOR 26.0 95% CI 3.62-186.5; p=0.001). The odds of having a symptomatic UTI were lower among peri/postmenopausal participants (aOR 0.13; 95% CI: 0.02-0.68; p=0.016) and among participants located in the Northeast U.S. (aOR 0.23; 95% CI 0.08-0.72; p=0.012).

Conclusions: Symptomatic, culture-proven UTI rates were not significantly different between participants who received antibiotics and those who did not. Factors associated with an increased risk of post-procedure UTI included older age, pre-menopausal status, self-catheterization, and BTX-A dose of 200 units.

Disclosure(s):

Elise B. Morocco, MD: No financial relationships to disclose

Lannah Lorraine L. Lua-Mailland, MD, MPH: No financial relationships to disclose

Adrienne Werth, MD: No financial relationships to disclose

Danielle Carr, MD: No financial relationships to disclose

Sarah Rabice, MD: No financial relationships to disclose

Sarah Ashmore, MD: No financial relationships to disclose

Vi Duong, MD: No financial relationships to disclose

Margaret Wilkes, MD: No financial relationships to disclose

Wesley Nilsson, M.D.: No financial relationships to disclose

Tanaz Ferzandi, MD, MBA, MA: No financial relationships to disclose

Presenting Author(s)

Elise B. Morocco, MD (she/her/hers)

Assistant Professor
Dartmouth Hitchcock Medical Center, United States

Disclosure(s): No financial relationships to disclose

Co-Author(s)

Lannah Lorraine L. Lua-Mailland, MD, MPH (she/her/hers)

Fellow
Cleveland Clinic Foundation
Cleveland, Ohio, United States

Disclosure(s): No financial relationships to disclose
Adrienne Werth, MD

Assistant Professor
University of Pennsylvania
Philadelphia, Pennsylvania, United States

Disclosure(s): No financial relationships to disclose
Danielle Carr, MD (she/her/hers)

Fellow
Mount Auburn Hospital
Cambridge, Massachusetts, United States

Disclosure(s): No financial relationships to disclose
SR

Sarah Rabice, MD (she/her/hers)

Fellow
University of Iowa Hospitals and Clinics
Iowa City, Iowa, United States

Disclosure(s): No financial relationships to disclose
Sarah Ashmore, MD

Fellow
Section Urogynecology and Reconstructive Pelvic Surgery, University of Chicago
Chicago, Illinois, United States

Disclosure(s): No financial relationships to disclose
Vi Duong, MD (she/her/hers)

Attending Physcian
Northwestern Medicine
Northbrook, Illinois, United States

Disclosure(s): No financial relationships to disclose
MW

Margaret Wilkes, MD (she/her/hers)

Fellow
University of Rochester Medical Center
Rochester, New York, United States

Disclosure(s): No financial relationships to disclose
WN

Wesley Nilsson, M.D.

Fellow
UConn Health
CHESHIRE, Connecticut, United States

Disclosure(s): No financial relationships to disclose
Tanaz Ferzandi, MD, MBA, MA

Director, Division of Urogynecology; Service Line Chief of Ob.Gyn at Keck Hospital
University of Southern California
Los Angeles, California, United States

Disclosure(s): No financial relationships to disclose