Doxorubicin belongs to the theophylline class of drugs, which can act as a bronchodilator by inhibiting phosphodiesterase and promoting the release of endogenous catecholamines and other mechanisms of action. The specific usage of the oral form of doxorubicin is: generally take 0.2-0.4g orally each time, twice a day, take about 1 week to observe the effect, and consider reducing or stopping the drug after the symptoms are relieved, up to two weeks. Because on the one hand, with longer use time, the number of receptors that can be bound in the body decreases and the effect gradually diminishes. On the other hand, the effect of doxorubicin is stronger, and its effect of bronchodilatation is 10-15 times that of aminophylline, and it is a long-acting drug with a long duration of action. Long-term use, especially overdose, is likely to accumulate in the body and cause serious adverse reactions, such as palpitations, panic, tachycardia, premature beats, nausea and vomiting and other gastrointestinal reactions. Therefore, the indications for doxorubicin should be strictly controlled, and the duration of use should be controlled, as well as the adverse effects should be closely observed.