New pharmacotherapy for treating overactive bladder: mirabegron and botulinum toxin

ABSTRACT

Overactive bladder (OAB) is a symptom-driven condition characterized by urinary urgency with or without urinary incontinence and a common problem that can significantly affect quality of life. Drugs that prevent acetylcholine-mediated involuntary detrusor contractions are the mainstay of OAB treatment, but several alternative therapeutic options have become established treatments for OAB. Mirabegron (a β3-adrenoceptor agonist) has a different mechanism of action from antimuscarinic agents. Recently published randomized controlled trials have shown that mirabegron is an effective and safe drug for the symptomatic treatment of OAB patients. Mirabegron represents a valid option both for patients with OAB who are antimuscarinics treatment-naïve, as well as for those who are unresponsive or intolerant to antimuscarinics. Intravesical injection of botulinum toxin A is an effective treatment for OAB that is refractory to antimuscarinics. Treatment with botulinum toxin A showed clinically relevant improvement in all OAB symptoms and health-related quality of life. It was generally well tolerated by most patients, and most treatment-related complications were acceptable. However, increased risk of a larger volume of post-void residual urine was noted in several patients and the possibility of chronic catheterization requires careful evaluation before treatment. In sum, recent options for management of OAB, mirabegron and intravesical injection of botulinum toxin A, expand the treatment options for the optimal treatment of each patient.