Nine-month-old babies take medication at the following intervals: First, the interval between the drug and food 0.5-1 hours or so, the food digested for a while and then oral medication will not stimulate the stomach and intestines, and is not prone to the symptoms of vomiting. Second, the interval between drugs should be analyzed according to the specific drugs, antiviral drugs are generally 4-6 hours oral once, cephalosporins or penicillin antibiotics are 8 hours oral once, macrolide antibiotics in azithromycin is 24 hours oral once, erythromycin is 8 hours oral once. Specific drugs are different, the interval time is different. Third, if it is between drugs oral, try to interval ten minutes after oral, to avoid simultaneous oral stimulation of pediatric gastrointestinal. The macrolide antibiotics and cephalosporin antibiotics must be separated by 3-4 hours before oral intake, to avoid mutual counteractivity.