Penicillin belongs to the β-lactam group of antibiotics and has antibacterial and bactericidal properties. Penicillin is commonly used clinically to treat infections caused by sensitive pathogens. Such as pharyngitis, tonsillitis, scarlet fever, endocarditis, dengue, cellulitis, puerperal fever caused by hemolytic streptococcus; pneumonia, otitis media, meningitis, bacteremia caused by pneumococcus; tetanus, gas gangrene caused by Clostridium difficile; syphilis; leptospirosis; return fever; diphtheria. A common adverse reaction to penicillin is an allergic reaction, with symptoms including rash, leukopenia, interstitial nephritis, asthmatic attacks, and serum sickness type reactions. Toxic reactions, Hirschsprung’s reaction, and therapeutic contradictions may occur in a small number of patients. The use of medication should be noted: patients allergic to penicillin is prohibited; need to carry out skin allergy test before using the drug, positive people are prohibited; liver and kidney dysfunction of patients with caution; infants with caution; the end of pregnancy, maternal caution; lactating women are contraindicated. If you need to use penicillin, it is recommended to consult a professional doctor, follow the doctor’s instructions for standardized treatment, not blindly self-medication.