Airway response to sublingual nitroglycerin in acute asthma.

To test the efficacy of sublingual nitroglycerin as a bronchodilator, we studied ten patients with acute asthma. After a baseline spirogram, each patient was given 1.2 mg of sublingual nitroglycerin, and subsequent spirograms were obtained a five-minute intervals for 15 minutes. Each patient was then given three subsequent doses of epinephrine (0.5 mg) subcutaneously at 15-minute intervals. Spirograms were obtained 15 minutes after each epinephrine dose. Forced expiratory volume at 1 s (FEV1) and forced vital capacity (FVC) did not change significantly following sublingual nitroglycerin, but both FEV1 and FVC improved significantly after epinephrine administration. Three patients experienced transient but severe hypotension after receiving sublingual nitroglycerin. The results suggest that sublingual nitroglycerin is not adequate initial therapy for asthmatic attacks and that the administration of sublingual nitroglycerin in acute asthma may be dangerous.