There are two major classes of decongestants commonly used in clinical practice, namely sympathomimetic amines and imidazoles. Their pharmacological effects are to constrict the blood vessels of the skin and mucous membranes and reduce the state of blood filling, with the aim of reducing bleeding in the operative cavity and improving nasal mucosal hypertrophy and nasal ventilation. Clinically used sympathomimetic drugs, including epinephrine hydrochloride and ephedrine, nasal drops with furosemide nasal drops, which is a mixture of furacilin and ephedrine solution. The commonly used drugs of imidazole class are hydroxymetazoline and nemetazoline, and the commonly used nasal drops are nemetazoline hydrochloride nasal drops. Nasal decongestants commonly used in ENT clinics generally cannot be used for more than a week to avoid the side effects of drug-dependent rhinitis.