Antibiotics May Not Be Needed Before Botox Bladder Injection

Kate Johnson

March 16, 2016

MUNICH — For patients being treated for neurogenic detrusor overactivity with repeated injections of onabotulinumtoxinA (Botox), antibiotics for asymptomatic bacteriuria might not be necessary, new research suggests.

"Currently, antibiotic prophylaxis is the standard and is recommended; however, the evidence for it with this kind of minimally invasive therapy is very limited," said Lorenz Leitner, MD, a neuro-urologist at the Spinal Cord Injury Center at the University of Zurich.

Because of the alarming increase in antibiotic resistance around the world, "any use of antibiotics should be critically considered," he told Medscape Medical News. In this population, "antibiotic prophylaxis seems not to be justified."

Dr Leitner presented the study findings here at the European Association of Urology (EAU) 2016 Congress.

"Further work in this area to confirm these findings would be helpful, but certainly the authors are to be congratulated on this very useful study," said EAU Secretary General Christopher Chapple, MD, from Sheffield Teaching Hospitals in the United Kingdom.

These findings "may well have an impact on our future clinical practice," Dr Chapple told Medscape Medical News.

Dr Leitner and his colleagues evaluated 273 consecutive treatment cycles in 154 patients, 95 of whom were male (62%). The neurologic disorders in the study cohort included spinal cord injury (66%), multiple sclerosis (13%), spina bifida (6%), and Parkinson's disease (4%).

Bladder emptying was achieved spontaneously by 12% of the cohort, with an in-dwelling catheter by 38%, and with intermittent self-catheterization by 50%.

Patients provided urine samples on the day of the first onabotulinumtoxinA injection, and none of the patients received antibiotic prophylaxis.

Those with "any sign of urinary tract infection, such as fever, putrid urine, or severe bladder pain, were not rejected but were referred to adequate treatment with injections postponed," Dr Leitner reported.

Most Patients Had Bacteriuria, Many Had Multiple Strains

A positive urine culture identified bacteriuria in 73% of patients. Bacterial strains included Escherichia coli (30%), Enterococcus faecalis (15%), Klebsiella pneumonia (10%), Proteus mirabilis (4%), and Aerococcus urinae (4%). Almost half the patients had more than one strain; 30% had two strains, 12% had three strains, and 6% had four strains.

There was no difference in outcomes between patients with and without bacteriuria, regardless of the number or distribution of bacterial strains.

Treatment of bacteriuria may not be clinically necessary.

Overall, adverse events at 6 weeks were uncommon in both the bacteriuria and no bacteriuria groups (5% vs 7%). Urinary tract infections were less common in the bacteriuria group than in the no bacteriuria group (4% vs 7%), but prolonged gross hematuria was more common in the bacteriuria group (1% vs 0%), as was autonomic dysreflexia (1% vs 0%) and bladder pain (1% vs 0%).

There was no difference in clinical and urodynamic efficacy at 6 weeks between the two groups (70% vs 70%).

On the basis of these findings, the use of antibiotics can be reduced in this study population, which "would minimize costs, reduce antibiotic resistance, and facilitate everyday clinical practice," Dr Leitner pointed out.

Phase 3 studies of onabotulinumtoxinA have shown "a very high bacteriuria rate in patients undergoing treatment, which do not appear to mirror findings in clinical practice," Dr Chapple explained.

The premise has been that there is a risk for infection "with any bacteria, either in the urinary bladder already or carried in," but this study suggests that the "treatment of bacteriuria may not be clinically necessary," he said.

The study was supported by the Swiss Continence Foundation, the Swiss National Science Foundation, Wings for Life, and Emily Dorothy Lagemann Stiftung. Dr Leitner and Dr Chapple have disclosed no relevant financial relationships.

European Association of Urology (EAU) 2016 Congress: Abstract 649. Presented March 13, 2016.


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