Mirabegron for Male Lower Urinary Tract Symptoms

Benign prostatic hyperplasia (BPH) is a common cause of lower urinary tract symptoms (LUTS) in men. Patients with BPH often present with a combination of obstructive and overactive bladder (OAB) symptoms. It is postulated that bladder outlet obstruction (BOO) from BPH results in concomitant OAB symptoms through ischemic induced variations in the response to neurotransmitters of both the detrusor and the urothelium. This altered response leads to the pathologic activation of the micturition reflex, generating sensory dysfunction and involuntary bladder contractions. Alpha-1 adrenoceptor antagonists (alpha-blockers) and 5-alpha reductase inhibitors (5-ARIs) are commonly used to treat the BOO caused by BPH. Anticholinergic agents are frequently used to treat concurrently OAB symptoms caused by the BOO. Unfortunately, anticholinergic medications demonstrate bothersome side effects and a theoretical risk of urinary retention. Basic science and clinical research has led to the development of a new class of pharmaceuticals for the treatment of overactive bladder with diminished risk of urinary retention and lacking many anticholinergic side effects. This novel compound, mirabegron (Mybertriq, Astellas Pharma US, Inc.), is a β₃-adrenoceptor agonist and represents a promising new class of oral agents designed for the treatment of OAB symptoms, with minimal effect on voiding.