Xamoterol is a partial agonist of β-adrenergic receptors (β-ARs) with an EC value of 80 nM for the generation of cyclic AMP (cAMP) in neonatal rat cardiomyocyte cultures. It increases spontaneous contraction of isolated rat right atria (EC = 4.67 nM). In vivo, xamoterol increases heart rate in beagle dogs (ED = 3.2 µg/kg) and in a rat model of spontaneous heart failure (ED = 6 µg/kg), an effect that is reversed by the selective β-AR antagonist betaxolol but not the selective β-AR antagonist ICI 118551 . Formulations containing xamoterol have been used in the treatment of heart failure.