Doxofylline, also known as Dosofitline, is an oxycyclopentyl methyl derivative of theophylline. It has a significant inhibitory effect on phosphodiesterase, and can directly act on bronchus and relax smooth muscle. Its effect is stronger than aminophylline, and has antitussis effect, and the action time is long and independent. No central, gastrointestinal and other adverse reactions, does not affect cardiac function. For bronchial asthma and other lung diseases with bronchospasm Chemicalbook disease. Rapid absorption, healthy adults once oral administration of this product 0.4g, blood concentration peak time is 1.22h. It is widely distributed in various organs, among which the lung is the highest. Excreted from the urine in its original form and as a metabolite, the main metabolite being beta-hydroxyethyltheophylline. t1/2 is 7.41h. Eating can reduce peak concentration (Cmax) and delay peak time (tmax).