Mirabegron is used in the treatment of Overactive bladder (OAB) . OAB is a collection of urinary symptoms, including frequent urination, urgent need to urinate, and inability to control urination. Miragron 25mg Tablet ER helps to treat uncontrollable contractions (spasms) of the bladder muscles that cause frequent urination, urgent need to urinate, and inability to control the passing of urine. It also relieves painful, or frequent urination and reduces the urgency to urinate that may occur with some infections of the urinary tract. This way it helps manage the overactive bladder symptoms efficiently. Mirabegron is a beta3 agonist drug that treats overactive bladder (OAB) symptoms. Learn about its dosages, side effects, drug interactions, warnings, and precautions from RxList. Mirbeg 25 Tablet ER helps to treat uncontrollable contractions (spasms) of the bladder muscles that cause frequent urination, urgent need to urinate, and inability to control the passing of urine. It also relieves painful, or frequent urination and reduces the urgency to urinate that may occur with some infections of the urinary tract. This way it helps manage the overactive bladder symptoms efficiently.