​Weekly medicine point - Azithromycin "take three and stop four"?

Why is azithromycin generally taken for three days and stopped for four days?

Azithromycin is a semi-synthetic macrolide antibiotic with a long half-life of up to 68 hours after oral administration. Continuous long-term use can easily lead to drug accumulation and side effects. Therefore, in clinical practice, azithromycin is generally taken for 3 days and stopped for 4 days. For patients, 12.5% ​​to 25% of azithromycin will still exist in the body 4 days after stopping the drug. Therefore, after taking the drug for 3 consecutive days, the drug still maintains an effective blood concentration in the body to exert its effect. A reexamination will be conducted after the 7th day, and the doctor will decide whether the next course of medication is needed based on the patient's condition.