Comparison of Methods for Prevention of Urinary Tract Infection Following Botox Injection

Comparison of Methods for Prevention of Urinary Tract Infection Following Botox Injection: a Non-Inferiority Trial

The Allergan Foundation, Society of Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction

Injection of OnabotulinumtoxinA (BTX-A) into the bladder is a widely used treatment option for patients with overactive bladder who have failed medical therapy. Urinary tract infection is the most common side effect of this procedure and therefore antibiotics are given around the time of injection in order to prevent these events. While antibiotics are commonly given at the time of injection, the duration of these antibiotic regimens are variable. The investigators propose a study to investigate different antibiotic protocols and their affect on the rate of urinary tract infection after injection.

Intravesical injection of OnabotulinumtoxinA (BTX-A) is a widely practiced third line therapy for non-neurogenic overactive bladder (OAB). However, a paucity of data exists regarding urinary tract infections (UTI), the most common adverse event following injection. The investigators propose a randomized, controlled cross-over trial to investigate the utility of commonly practiced antibiotic protocols and simultaneously derive information regarding risk factors for post-procedural UTIs and their affect on treatment efficacy. The investigators plan to initiate a prospective, randomized non-inferiority cross-over trial, in which a participant receives peri-procedural antibiotics exclusively at the time of one injection, and then at a subsequent injection, completes a three-day course of antibiotics post-operatively in addition to the peri-procedural dose. Enrollment is planned to achieve a total of 68 participants. Participants will be evaluated at 3 weeks and 3 months following injection to identify adverse events and treatment success. Inter-injection time will be measured and used a surrogate for efficacy over multiple injections. These results, in addition to filling a void in current literature regarding the increasingly utilized treatment with BTX-A, have the potential to modify clinical practice regarding antibiotic use and decrease rates of adverse events. The means to stratify patients based on their specific risk of UTI may be used to facilitate antibiotic stewardship and improve patient outcomes.

Patients receive a peri-procedural dose of antibiotics and an extended (3-day) course of antibiotics to be taken post-procedurally.

One the day of injection, after eligibility is determined and consent obtained, research staff will refer to the randomization list to determine to which arm the patient is randomized. Patients randomized to the "Procedural Antibiotics Only" arm will receive a single dose of trimethoprim/sulfamethoxazole (800/160mg) peri-procedurally at the time of the first injection.

Patients randomized to the "Extended Antibiotics" arm will receive one dose of trimethoprim/sulfamethoxazole peri-procedurally and additionally be prescribed trimethoprim/sulfamethoxazole twice daily for three days. Patients who are allergic will receive amoxicillin/clavulanic acid (875/125mg) twice daily for three days. If allergic to both of the above antibiotics, patients will receive 100mg nitrofurantoin BID for three days. For their second injection, they will receive peri-procedural antibiotics only.

Patients will receive injection of OnabotulinumtoxinA (BTX-A) per standard clinic practice protocol. All patients will undergo injection per a standardized protocol of 1ml injection per site at a concentration of 10 units/ml.

Development of urinary tract infection as measured by a urine culture with >10^5 bacterial colonies in the setting of symptoms. This outcome will be assessed at the 3 week post-injection visit by a voided urine culture.

Development of urinary retention post-procedurally as measured by post void residual volume using a bladder scanner in clinic.

Development of multiple urinary tract infections after injections, measured by a urine culture and defined as a urine culture with >10^5 bacterial colonies in the setting of urinary symptoms.

Inclusion criteria: ≥ 18 years of age Medication refractory OAB, identified per American Urological Association guidelines Exclusion criteria: Post void residual urine >150ml on two occasions Untreated, symptomatic UTI Comorbid neurological conditions, including spinal cord injury, systemic neurologic illnesses (i.e. multiple sclerosis, Parkinson's disease) or central nervous system disease (i.e. brain tumor, stroke) Prior pelvic irradiation Current or prior bladder malignancy Hematuria lacking a clinically appropriate evaluation Chronic indwelling or intermittent catheterization