Erythromycin as a commonly used antibiotic for infants is mainly reflected in two aspects: first, pharmacological effects, erythromycin can anti-infection, for common bacterial infections or have a certain antibacterial effect, for mycoplasma, pertussis bacillus effect is relatively good. The second side effect, because erythromycin has a gastric power effect, so some infants may appear after eating it, the possibility of increased intestinal peristalsis caused by diarrhea, abdominal distension, some may also cause gastrointestinal reactions appear nausea, vomiting, appetite loss. Erythromycin in high doses or for a long time may also cause damage to liver and kidney functions, which should also be noted. Some infants are also prone to symptoms of erythromycin allergy, resulting in a rash when using erythromycin. There are oral and intravenous erythromycin, the oral and intravenous side effects are relatively more, and there is also erythromycin ointment for topical use on the skin, which basically has fewer side effects and can be used more safely.