Labetalol, beta blockers, and acute deterioration of chronic airway obstruction.

The effects on lung function of labetalol (a combined alpha and beta adrenergic receptor blocker) and three beta adrenergic receptor blockers (propranolol, atenolol, metoprolol) have been assessed in patients with chronic airflow obstruction using a double-blind trial. With the dosages used, all drugs produced an equivalent fall of blood pressure. Propranolol was the only drug that significantly increased airways obstruction (FEV1, specific airways resistance). Following salbutamol, labetalol was associated with a significantly greater improvement of airflow than either propranolol or metoprolol. On these acute studies, the order of preference for beta blocking drugs in management of hypertension in patients with obstructive airways disease, would be labetalol, (atenolol) or (metoprolol) and then propranolol.