Combined alpha/beta blockers inhibit beta receptors together with alpha-1 receptors. The clinically important members are labetalol and carvedilol; their balance of receptor blockade and approved uses differs.

Beta-1 blockade slows heart rate and reduces contractility and renin release; beta-2 blockade can increase airway resistance. Concurrent alpha-1 blockade reduces arteriolar and venous tone, lowering vascular resistance and limiting the rise in peripheral resistance that can accompany pure beta blockade.

Labetalol and carvedilol are the principal examples. Carvedilol also has antioxidant and other ancillary properties, but its clinically relevant identity remains combined alpha-1 and beta blockade.

Carvedilol is used in selected patients with heart failure with reduced ejection fraction and in hypertension. Labetalol is used for hypertension and is commonly chosen when rapid blood-pressure control is needed, including in pregnancy-associated severe hypertension according to local protocols.

Adverse effects include bradycardia, hypotension, dizziness, fatigue and orthostatic symptoms. Beta-2 blockade may provoke bronchospasm, while excessive blockade can worsen acute decompensated heart failure or cause conduction disturbance.

Avoid or use specialist caution in severe bradycardia, advanced atrioventricular block without pacing, cardiogenic shock, active decompensated heart failure and bronchospastic disease. Treatment should not be stopped abruptly after chronic use.