The half-life of a drug like penicillin is about 30 minutes. The half-life of a drug is the time it takes for the amount of the drug to decrease to half in the body, and it is important to match the drug and choose the time for the second dose. Penicillin is a highly effective, low-toxicity, widely used antibiotic drug, so after the body has inflammation or respiratory tract infections and other problems, it is possible to use penicillin this drug to achieve anti-inflammatory and treatment to control the purpose of the disease. However, because some people are allergic to penicillin, most people need to take a skin test before injecting penicillin to see if they are allergic to the drug. If they are allergic after the skin test, they should choose other cephalosporin or quinolone antibiotics for treatment.