Reduced respiratory responses to carbon dioxide after propranolol: a central action

In a double-blind study in six subjects propranolol significantly reduced the respiratory sensitivity to carbon dioxide rebreathing. This effect seems to have been due to beta-adrenergic blockade, since it was not seen with D-propranolol. In two subjects increasing doses of propranolol caused progressive reductions in respiratory sensitivity to values below normal and similar to those of patients with ventilatory failure. These changes are probably due to a central action of propranolol.