Cetirizine hydrochloride drops are used in the treatment of cough. Cetirizine hydrochloride drops are orally administered preparations, which mainly have the ability to block the release of histamine and have certain anti-allergic effects. Clinically, it is able to eliminate the inflammatory reaction of congestion and edema in the airway mucosa, and due to this effect, it can be used in the treatment of allergic cough. The main diseases commonly associated with allergic cough are wheezing bronchitis and cough variant asthma. It is able to reduce the congestion and edema of the airways, and even inhibit the contraction and spasm that occurs in the bronchial smooth muscle, and is able to keep the airways open. Therefore, cough caused by these diseases can be treated with cetirizine hydrochloride drops as an option.