Life-threatening cold and exercise-induced asthma potentiated by administration of propranolol

We present two patients with acute respiratory failure secondary to cold and exercise-induced asthma. Neither patient had a prior history of asthma, and both had recently been placed on therapy with propranolol for treatment of hypertension. We discuss the postulated mechanism of bronchospasm in these patients. In addition, we urge aggressive searching for any change in respiratory symptoms in patients receiving propranolol.