Aminophylline is a classic bronchodilator and has long been used in the treatment of HAPE. Aminophylline can dilate the bronchus, decrease hypoxic pulmonary hypertension, enhance diaphragm function, suppress lipid peroxidation and hypoxia-induced pulmonary vascular inflammation, enhance cardiac function and diuresis, clear bronchial mucus, and subsequently resolve moist rales. Unlike other bronchodilators, aminophylline can dilate both the bronchus and vascular smooth muscle; hence, it is preferred over other bronchodilators for the treatment of HAPE.