The most effective way to stop cough is to eat sugar. When coughing, it contains a piece of hard candy. The syrup that is continuously swallowed can form a protective layer in the throat to reduce throat irritation. It is also possible to drink honey water, but it is not as durable as containing sugar.
The main antitussive syrup used in clinical practice mainly relies on codeine to paralyze the nerves. Drinking a large amount has the risk of addiction.
The most dangerous is licorice tablets, which are directly added to opium, which is easily addicted.