Azithromycin with 3 days to stop 4 days has no clear clinical basis, patients need to follow the doctor’s instructions for medication. Azithromycin belongs to the second generation of macrolide antibiotics, clinically used in the treatment of sensitive bacteria caused by the upper and lower respiratory tract, mucous membrane infections, such as pharyngitis, mycoplasma pneumonia, acute pharyngitis, acute tonsillitis. Azithromycin with 3 days stop 4 days in the clinic is not a clear basis, azithromycin’s half-life is long, antibiotic after effect is strong. The plasma half-life after single-dose administration is 35 to 48 hours, stopping 3 to 5 days after taking azithromycin, to 12 days, there is still a certain concentration of the drug in the leukocytes and phagocytes. Azithromycin has a strong post-antibiotic effect, i.e., the effect that after a brief contact between bacteria and antibiotics, the antibiotic concentration decreases and bacterial growth is still continuously inhibited. Patients need to follow the doctor’s instructions to use the drug, can not arbitrarily stop the drug.