Azithromycin and cephalosporin can be used together. Azithromycin and erythromycin belong to the same class of drugs, both belong to macrolide antibiotics, which are bacteriostatic agents and can quickly inhibit the growth and reproduction of bacteria. Cephalosporins belong to the beta-lactam antibiotics, and beta-lactam antibiotics belong to the reproductive phase bactericides. When macrolide antibiotics and beta-lactam antibiotics are used together, macrolide drugs will rapidly inhibit the growth and reproduction of bacteria, thus leaving bacteria in a quiescent state, resulting in a weakening of the bactericidal effect of the reproductive bactericides beta-lactam drugs, the two together play not a synergistic or additive antibacterial effect, but an antagonistic effect, usually these two types of antibiotics are not used together. However, azithromycin, an exception among macrolides, has little effect on cephalosporins and can be used together with cephalosporins, which is clearly recommended in the 2016 edition of the Guidelines for the diagnosis and treatment of community-acquired pneumonia in adults in China.