This product is a first-generation cephalosporin, which has good antibacterial effect on some strains of Gram-positive cocci such as non-penicillinase-producing and penicillinase-producing Staphylococcus aureus, coagulase-negative Staphylococci, group A hemolytic streptococci, Streptococcus pneumoniae and viridans streptococci. Anaerobic Gram-positive bacteria are mostly sensitive to this product, while Bacteroides fragilis is resistant to it. Methicillin-resistant Staphylococci and Enterococci are resistant to this product. The effect of this product on Gram-positive and Gram-negative bacteria is similar to that of cephalexin. This product has a certain effect on gonococci and is also active against enzyme-producing gonococci; its activity against Haemophilus influenzae is poor.

Cephalexin is a first-generation cephalosporin with an antibacterial spectrum similar to that of cephalothin, but its antibacterial activity is poorer than that of the latter. Except for Enterococcus and methicillin-resistant Staphylococci, most strains of Streptococcus pneumoniae, hemolytic Streptococcus, and Staphylococcus aureus that produces or does not produce penicillinase are sensitive to this product. This product has a good antibacterial effect on Neisseria, but Haemophilus influenzae is less sensitive to this product; this product has a certain antibacterial effect on some Escherichia coli, Proteus mirabilis, Salmonella and Shigella. The remaining Enterobacteriaceae, Acinetobacter, Pseudomonas aeruginosa, and Bacteroides fragilis are resistant to this product. Fusobacterium and Veillonella are generally sensitive to this product, and anaerobic Gram-positive cocci are moderately sensitive to this product. The oral median lethal dose of cephalexin in mice is 2600 mg/kg.

This product is a broad-spectrum semi-synthetic cephalosporin antibiotic. Its activity against penicillinase-producing Staphylococcus aureus, group A hemolytic streptococci, viridans streptococci and Staphylococcus epidermidis is the same as that of cefadroxil, and its antibacterial effect against non-enzyme-producing Staphylococcus aureus and pneumococci is 2 to 4 times stronger than that of cefadroxil. Its activity against Gram-negative bacilli, including Escherichia coli and Klebsiella pneumoniae, is stronger than that of cefadroxil, and is similar to that of cefadroxil. Its activity against Proteus mirabilis, Salmonella and Shigella is stronger than that of cefadroxil. 2.9 to 8 mg/L of this product can inhibit all Haemophilus influenzae, including strains resistant to ampicillin. Moraxella catarrhalis and Neisseria gonorrhoeae are very sensitive to this product. Indole-positive Proteus, Serratia, Acinetobacter and Pseudomonas aeruginosa are all resistant to this product. The mechanism of action of this product is to inhibit the synthesis of bacterial cell walls.

Antibacterial drug. The beta-lactamase produced by Staphylococcus aureus is relatively stable, so it has a strong antibacterial effect on Gram-positive bacteria; the beta-lactamase produced by Gram-negative bacteria is unstable, so it has a weaker effect on Gram-negative bacteria and is ineffective against Pseudomonas aeruginosa and anaerobic bacteria.

It has a broad spectrum of antibacterial activity against Gram-positive and Gram-negative bacteria, especially against Escherichia coli, Klebsiella, Haemophilus influenzae, Proteus and Bacteroides fragilis. Its mechanism of action is that it shows a strong affinity for penicillin-binding protein, which is the usual point of action of beta-lactam antibiotics, inhibits cell wall synthesis, binds to peptidoglycan, inhibits the binding of peptidoglycan to lipoprotein to promote bacteriolysis, and shows a strong bactericidal effect in a short time. This product shows antibacterial effect on bacteria during the proliferation period and the early stage of the stable period, and has a bactericidal effect at concentrations lower than the MIC, and lyses bacteria in a short time. The antibacterial effect in vivo is stronger than the prediction of MIC.