If there is a serious bacterial infection, you can follow medical advice to apply both erythromycin and cephalosporin for treatment. Erythromycin belongs to macrolide antibiotics, which inhibit bacterial growth by inhibiting bacterial protein synthesis, and cephalosporin belongs to cephalosporin antibiotics, which are semi-synthetic antibiotics, and achieve antibacterial by inhibiting bacterial cell wall synthesis. 1. Erythromycin: mainly against bacteria on the skin surface, such as Staphylococcus, Streptococcus pneumoniae, and Haemophilus influenzae, which is common to cause pneumonia, and atypical pathogens, such as Mycoplasma, Chlamydia and Legionella, etc., have good antibacterial effect; 2. Cephalosporin: cephalosporin antibacterial drugs, can inhibit the production of bacterial cell wall, to achieve the purpose of sterilization or inhibition of bacteria, the general side effects on the human body is small, with a wide antibacterial spectrum, strong antibacterial effect, resistance to penicillin enzyme, allergic reactions less than penicillin class and other advantages. Cephalosporin antibiotics are highly effective and low toxicity, and are more widely used clinically, both for some Gram-positive bacteria and Gram-negative bacteria, they have better antibacterial effects. If the clinical condition requires, erythromycin and cephalosporin can be used together. The combined application of both can expand the antibacterial spectrum and increase the antibacterial efficacy to a certain extent, such as some special and serious infections, such as chlamydial pneumonia and mycoplasma pneumonia, etc., erythromycin or minocycline combined with cephalosporin is often used for treatment, which can achieve better efficacy. In addition, both erythromycin and cephalosporin need to be skin tested before application. Those who are allergic to cephalosporin or have a history of anaphylaxis and immediate reaction to erythromycin should be prohibited, and care should be taken not to drink alcohol before and after taking cephalosporin to avoid shock or syncope, or even life-threatening.