Fulusi, also known as acetylcysteine effervescent tablets, the drug is a dissolving agent for mucous phlegm, has a strong mucolytic effect, which can break the glycoprotein chain in phlegm, thus reducing the viscosity of phlegm, liquefying the phlegm and making it easy to cough up out of the body, and also maintains a certain level of glutathione in the organism. The drug is mainly used for the treatment of chronic respiratory diseases that secrete large amounts of thick sputum, such as acute exacerbation of chronic bronchitis, acute exacerbation of chronic obstructive pulmonary disease, emphysema, alveolus, lung abscess, bronchiectasis with infection, interstitial pneumonia, interstitial lung fibrosis and so on.