The full name of β-agonists is β-adrenoceptor agonists. β-agonists bind to beta receptors on the heart and smooth muscle tissue. They also play an important role in other tissues, especially bronchial smooth muscle (relaxation), liver (stimulation of glycogen breakdown) and kidney (stimulation of renin release). β-agonists mimic sympathetic epinephrine that can stimulate the action through β-adrenergic receptors. In general, the role of β-agonists is cardiac stimulation and systemic vasodilation. β-agonists are catecholamine drugs, which have low bioavailability and must be injected intravenously.
