There are nearly 100 kinds of antibiotics, and like other drugs, they also have certain adverse reactions. The main ones are as follows: (1) Allergic reaction. Penicillin, streptomycin, vancomycin and so on can make people have allergic reactions, which can be life-threatening in serious cases. Allergic reactions caused by antibiotics are common as drug rash, dermatitis and drug fever. (2) Toxic reactions. Including auditory nerve damage, hematopoietic system disorders, renal damage, liver damage and gastrointestinal reactions. The nature and degree of toxic reactions vary according to the type of drug and individual patient differences. (3) Secondary infections. It is more likely to occur in the elderly, infants and young children, the frail, those who have abdominal surgery and those who abuse antibiotics. Secondary infections are generally more difficult to control and are very dangerous. (4) Drug resistance. Most bacteria are resistant to antibiotics. With the wide application of antibiotics and irrational use of antibiotics resulting in the abuse of antibiotics, resulting in an increasing number of drug-resistant strains, and even the emergence of superbugs, affecting the treatment of the disease, or even due to the lack of sensitive antibiotics to control the infection and produce serious consequences. (5) Local irritation. Most of the intramuscular injection of antibiotics can cause local pain, and intravenous injection may also cause thrombophlebitis. It can be seen that antibiotics must be used rationally, never as a “panacea” randomly.