Aminophylline is a 2:1 molar complex of the bronchodilator theophylline and ethylenediamine. Ethylenediamine increases the water solubility of theophylline, and aminophylline typically presents as a dihydrate.

Compared to anhydrous theophylline, aminophylline is less potent and has a shorter half life. It is primarily indicated for the treatment of airway obstruction in asthma and chronic obstructive pulmonary disease (COPD). Aminophylline acts as a nonselective adenosine receptor antagonist and a phosphodiesterase inhibitor.

Aminophylline is administered in hospital settings, often in combination with other therapies, to address acute symptoms of asthma, bronchitis, emphysema, and other pulmonary diseases. Aminophylline belongs to the bronchodilator class of drugs.