Levohypropizine is a chiral antitussive drug. It inhibits the cough reflex by acting on the C-fiber in the respiratory tract. It is clinically used for the treatment of severe dry cough without sputum. Compared with other existing antitussive drugs, it is a peripheral antitussive drug with almost no effect on the central system. It has good selectivity, strong antitussive effect, and no drowsiness, respiratory depression, respiratory depression Compared with racemate, it has less side effects.