The beta-3-sympathicomimetic drug Mirabegron is currently available as Betmiga® and indicated to treat hyperactive bladder. It is available as a slow release tablet in a 25 mg and 50 mg formulation. Sympathicomimetic drugs are known to relax the smooth muscle in several areas of the human body and are therefore used for inhalation in patients with asthma or as described for this drug to relax the smooth muscle of the bladder to treat urge incontinence. β3-Adrenoceptors mediate a negative inotropic effect in human ventricular cardiomyocytes, which is opposite to that of β1- and β2-adrenergic receptors. Unlike beta1/2-mimetics, that have significant cardiovascular side effects (including hypertrophy), beta3-mimetics have been reported to protect from hypertrophy and are only associated with some risk of tachycardia and palpitations in some patients.