Combining mirabegron and solifenacin for the treatment of overactive bladder

This study investigated the effect combining mirabegron (Myrbetriq) and solifenacin (Vesicare) to treat overactive bladder (OAB). They found that combining mirabegron and solifenacin was more effective than solifenacin alone and was well-tolerated.

To treat overactive bladder (OAB), patients are prescribed medication to help control the production of urine and relax the bladder muscle. Anti-muscarinic drugs are the first line of treatment for OAB. They act by relaxing the bladder muscle which reduces the urge to urinate. Dry mouth and eyes, constipation and dizziness are side effects associated with anti-muscarinic drugs. Solifenacin is an anti-muscarinic drug used to treat OAB.

Another type of drug that can treat OAB are beta3-adrenoreceptor agonists. By targeting these receptors the bladder muscle relaxes and reduces the need to urinate. Mirabegron is a beta3-adrenoreceptor. Whether a combination of these two types of therapies is more effective than one is still under investigation.

This study investigated the effects of combining solifenacin and mirabegron to treat OAB.

This study included 1306 patients with OAB. After a two-week washout period, patients were assigned to their treatment group. Patients received either placebo (substance with no active effect), solifenacin (2.5, 5 or 10 mg) alone, or in combination with mirabegron (25 or 50 mg) over a 12-week period. The amount of urine released during urination, the number of urinations and the number of incontinence episodes were analyzed at the beginning and end of the trial.

Combination treatment with solifenacin and mirabegron significantly reduced the volume of urine released compared to 5 mg solifenacin alone. Combination treatment with solifenacin and mirabegron reduced the number of urinations compared to 5 mg solifenacin and placebo groups. At the end of the trial, the number of incontinence episodes was reduced in all groups. Only the combination of 5mg/25mg solifenacin and mirabegron was more effective than 5mg solifenacin in reducing the number of incontinence episodes.

The most commonly reported side effects included dry mouth, hypertension (high blood pressure) and constipation.

This study concluded that combining mirabegron and solifenacin was more effective than solifenacin alone and was well-tolerated.

This study was conducted exclusively in white patients so the results may not extend to other ethnicities. The number of patients that reported having incontinence at the beginning of the study was low. Larger studies are needed to determine the effects of these drug combinations on incontinence.

If you have concerns or questions regarding treatment for OAB, please discuss with your doctor.