FDA Okays Botox (OnabotulinumtoxinA) for Overactive Bladder
Approval expands drug’s current indications (Jan. 18)
The FDA has expanded the approved use of Botox (onabotulinumtoxinA, Allergan, Inc.) to treat adults with overactive bladder who cannot use or do not adequately respond to anticholinergics.
Overactive bladder is a condition in which the bladder squeezes too often or squeezes without warning. Symptoms include urinary incontinence, feeling the sudden and urgent need to urinate, and frequent urination. The disorder affects an estimated 33 million men and women in the U.S.
When Botox is injected into the bladder muscle, it causes the bladder to relax, increasing the bladder’s storage capacity and reducing episodes of urinary incontinence. Injecting the bladder with Botox is performed using cystoscopy, a procedure that allows a clinician to visualize the interior of the bladder while Botox is being injected.
The safety and effectiveness of Botox for the new indication were established in two clinical trials involving 1,105 patients with symptoms of overactive bladder. The patients were randomly assigned to receive injections of 100 units of Botox (20 injections of five units each) or placebo.
After 12 weeks, patients treated with Botox experienced urinary incontinence an average of 1.6 to 1.9 times less per day than patients treated with placebo. Botox-treated patients also needed to urinate on average 1.0 to 1.7 times less per day and expelled an average of about 30 milliliters more urine than those treated with placebo.
Treatment with Botox can be repeated when the benefits from the previous treatment have decreased, but there should be at least 12 weeks between treatments.
Common side effects reported during clinical trials included urinary tract infections, painful urination, and incomplete urinary retention. Patients who develop urinary retention may need to use a catheter until the condition resolves. Patients being treated for overactive bladder with Botox should not have a urinary tract infection and should take antibiotics before, during, and for a few days after Botox treatment to lower the chance of developing an infection from the procedure.