When it comes to the choice of cough syrup, children can easily accept it because of its sweet taste. Some parents often give their children excessive amounts of alcohol when they have a cold or cough, thinking that they will get better quickly, but they do not know that this will lead to adverse reactions. In addition, since the syrup contains more than 75% sugar, diabetic patients cannot take it, and patients with purulent skin infections should also use it with caution. Cough syrup should not be taken before meals, because sugar can promote the secretion of digestive juices, make the stomach full and affect appetite. Since the antitussive effect of Chinese patent medicine cough syrup partly relies on the syrup covering the surface of the pharyngeal mucosa to reduce the irritation of inflammation to the mucosa and relieve coughs, water will dilute the medicine and weaken the antitussive effect, so it is not advisable to drink water immediately after taking it.