Intradetrusor injection of onabotulinumtoxinA, which is performed through a cystoscopic procedure, has been demonstrated to be efficacious in the treatment of both neurogenic and non-neurogenic overactive bladder (OAB), and is FDA approved as a treatment for overactive bladder. Intradetrusor of onabotulinumtoxinA is currently standard of care of patients with OAB who have persistent OAB symptoms despite behavioral therapies and oral medication treatments for OAB. As one of the main adverse events associated with intradetrusor injection of onabotulinumtoxinA is UTI, and published guidelines for cystoscopic procedures with manipulation recommend the use of prophylactic antibiotics, a single dose of prophylactic antibiotic is administered prior to this procedure. However, these recommendations are primarily based on data from randomized controlled trials (RCTs) involving antimicrobial prophylaxis during transurethral resection of the prostate. A previously published prospective study demonstrated that the rate of post-procedural UTI did not differ amongst patients with neurogenic bladder who did not receive prophylactic antibiotics and were asymptomatic for UTI, regardless of whether they had sterile urine cultures or asymptomatic bacteriuria, suggesting that patients who are not symptomatic for UTI may not require antibiotic prophylaxis prior to intradetrusor onabotulinumtoxinA injection. Studies have reported that up to 50% of antibiotic usage is inappropriate, leading to unnecessary exposure of patients to potential complications of antibiotic therapy, including Clostridium difficile infection which can cause recurrent diarrhea that may progress to sepsis and death, increasing antibiotic resistances, as well as dermal/allergic and gastro-intestinal manifestations. Therefore, in an effort to optimize antibiotic use, the investigators propose a prospective, randomized study to formally evaluate the differences in UTI frequency in subjects who have a negative urinalysis and are not symptomatic for UTI and receive prophylactic antibiotics at the time of intradetrusor onabotulinumtoxinA injection compared to those who do not receive prophylactic antibiotics at the time of injection. The proposed study seeks to evaluate the current practice standard of antibiotic prophylaxis prior to intradetrusor onabotulinumtoxin injection.