Girlfriend fever to go to two injections of penicillin is not necessarily effective, whether the penicillin is effective need to be based on the cause of the disease to determine. Fever is mainly divided into infectious and non-infectious two kinds, which leads to infectious fever mainly to infectious pathogens, such as bacteria, viruses, fungi, etc.; non-infectious fever causes are mainly tumors, allergic reactions, endocrine metabolic diseases. Treatment of fever needs to be based on the cause of the disease. Penicillin is an antibacterial drug, so it is effective for fever caused by bacterial infection, if it is viral infection or non-infectious fever, the effect of using penicillin treatment is not obvious. Fever is not recommended to use antibiotics immediately for treatment, low and medium fever can take physical cooling methods, high fever can be medication to reduce fever. Long-term use of antibiotics can lead to bacterial resistance, intestinal flora dysbiosis and other adverse effects. Fever or accompanied by uncomfortable symptoms, it is recommended to go to the hospital for examination and treatment, and follow the doctor’s instructions to take medication.