How effective are Botox injections for overactive bladder symptoms?

This study analyzed onabotA (onabotulinumtoxinA [Botox]) in treating overactive bladder symptoms (OABs). Authors reported that onabotA significantly reduced OABs and can be recommended as a third-line therapy.

Bladder muscle overactivity is characterized by urinary urgency and is often associated with urinary incontinence. OnabotA is a muscle paralyzer that can treat OABs. It is usually a second- to third-line therapy for patients not responding to behavioral therapy, physical therapy, or drug therapies. OnabotA is injected directly into the bladder muscle, causing it to relax and reduce urinary symptoms. More high-quality evidence is needed to confirm the safety and effectiveness of onabotA injections in treating OABs.

The results of 11 separate studies involving a total of 2,149 patients with OABs were pooled into a single analysis. Patients were randomly assigned to receive either an onabotA injection or placebo (a control drug with no active effect). Changes in OABs were compared at 12 weeks.

Overall, patients treated with onabotA showed 0.8 fewer incontinence episodes compared to placebo. 

Patients treated with onabotA had 1.26 fewer urge episodes than placebo. Patients treated with onabotA also had an average of 0.56 fewer episodes of urinary frequency.

The risk of urinary retention (a temporary inability to pass urine that requires treatment) following onabotA increased 11.5-fold compared to placebo. The risk of a urinary tract infection increased 2.7-fold compared to placebo. Higher doses of onabotA did not increase the rate of side effects.

Authors concluded that onabotA reduced OABs more than placebo. Treatment was also associated with an increased rate of side effects. Overall, onabotA can be recommended as a third-line therapy for overactive bladders.