临床上绝大部分镇咳药只能使严重的咳嗽减轻或缓解。由于很多有咳嗽症状的患者都伴有黏痰,单独使用镇咳药往往止住了咳嗽,但是由于抑制了咳嗽使痰液不能从呼吸道排出,有可能造成气道的阻塞和呼吸困难,从而加重病情,所以在提到镇咳药的同时,祛痰药也是不可不提的。临床上常用的祛痰药有以下几类: Clinically, most antitussive drugs can only reduce or alleviate severe cough. Since many patients with cough symptoms are associated with phlegm, cough is often stopped by the use of antitussives alone, but due to cough suppression, sputum can not be excreted from the respiratory tract, which may cause airway obstruction and dyspnea, which aggravates Illness, so when it comes to antitussive medicine, expectorant medicine is also a must. Expectorant drugs commonly used in clinical have the following categories: