Strong cough suppressant will not be immediately effective, according to pharmacokinetics, the general drug concentration peaks in 20 minutes to 1 hour of oral intake, which can achieve the effect of cough suppression. Cough is a protective reflex to keep the airways clean and clear. It is recommended that before applying cough suppressants, you should look for the cause of the cough, rather than just stopping and suppressing the cough. Strong cough suppressants are also known as cough suppressants. Central cough suppressants include codeine phosphate and dextromethorphan hydrobromide; peripheral cough suppressants include nalcotine hydrochloride. The above drugs take effect in about 20 minutes after oral intake, and the drug concentration reaches the highest after 1 hour of oral intake, which usually lasts for several hours. For patients without sputum, chronic cough is not easy to control, in order to avoid complications caused by severe cough, can be used to suppress cough medicine treatment. If the cough is accompanied by sputum, expectorants should be used, and cough suppressants should be used with caution, otherwise the sputum will not be easily coughed up and will easily be followed by bacterial infections. Cough needs to distinguish between dry cough or phlegm cough, not blindly use cough suppressants, so as not to aggravate the condition.