Aminophylline is a drug combination consisting of bronchodilator theophylline and ethylenediamine in 2: 1 ratio. It is a kind of non-selective adenosine receptor blocker, histone deacetylase activator and phosphodiesterase inhibition. It is mainly indicated for the treatment of various kinds of lung diseases including asthma, COPD, chronic bronchitis and emphysema. Aminophylline exerts its effect through the component of theophylline in vivo. Theophylline can relax the smooth muscle of the bronchial airways and pulmonary blood vessels. It can competitively inhibits type III and type IV phosphodiesterase (PDE), which breaks down cyclic AMP in smooth muscle cells, possibly leading to bronchodilation. Theophylline also binds to the adenosine A2B receptor to block the adenosine mediated bronchoconstriction. Furthermore, during the inflammatory states, theophylline can activate the histone deacetylase to prevent transcription of inflammatory genes that require the acetylation of histones to initiate the transcription.