Penicillin is an antibiotic that inhibits bacterial cell wall synthesis and has a bactericidal effect. It can be used to treat infectious diseases caused by sensitive bacteria such as pneumonia, otitis media, dengue, syphilis, gonorrhea, meningitis, tetanus, etc., and can also be used for the prevention of infective endocarditis. There can be side effects of rash, asthma, convulsions, coma, leukopenia, heart failure, anaphylaxis. A penicillin skin test is required before administration. When large quantities of the drug are used, blood electrolytes should be closely monitored to prevent electrolyte disorders. The drug is strictly prohibited to be paired with heavy metals such as copper, mercury, zinc, etc. There are also interactions with chloramphenicol, aspirin, warfarin, erythromycin, probenecid and other drugs when used in combination. It is prohibited for those with positive penicillin skin test; prohibited for those who are allergic to penicillins; prohibited for patients with infectious mononucleosis. The drug can be secreted through breast milk and may affect the embryo, so nursing women, pregnant women and women who may become pregnant should be carefully considered when using the drug. Breastfeeding women should stop breastfeeding if using the drug. If you need to use the drug, please strictly follow the doctor’s instructions to take the drug, do not self-medication.