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.

It binds to the 50s ribosome subunit of sensitive microorganisms and interferes with their protein synthesis (without affecting nucleic acid synthesis). It is effective against a variety of pathogens, including Gram-positive aerobic microorganisms, Gram-negative aerobic microorganisms, anaerobic bacteria, sexually transmitted disease microorganisms and other microorganisms.

Gastrointestinal motility effects: Esophagus: This product can enhance esophageal motility and lower esophageal sphincter tension; This product can prevent gastric contents from refluxing into the esophagus and improve esophageal clearance; Stomach: This product can increase gastric and duodenal contractility and coordination between the antrum and duodenum; This product can reduce duodenal-gastric reflux; This product can improve gastric and duodenal emptying; Intestine: This product can enhance intestinal motility and promote small and large intestine transit. Other effects: Since this product lacks cholinergic effects, it does not increase basal and pentagastrin-induced gastric acid secretion; Since this product relatively lacks dopamine antagonist properties, it has almost no effect on plasma prolactin levels.

A semi-synthetic antibiotic of the first generation of cephalosporins. Its antibacterial mechanism is to achieve the purpose of sterilization by interfering with the synthesis of cell walls. It generally has a strong antibacterial effect on Gram-positive bacteria, and also has a certain antibacterial effect on Gram-negative bacteria such as Escherichia coli and Shigella dysenteriae. Pseudomonas aeruginosa and Acinetobacter are resistant to this product.

This product is a second-generation cephalosporin antibiotic. After oral administration, it is hydrolyzed into cefuroxime under the action of esterase to exert antibacterial effect. Its activity against Gram-positive cocci is similar to or slightly worse than that of first-generation cephalosporins, but it is stable against beta-lactamase produced by staphylococci and Gram-negative bacilli. Sensitive bacteria include most positive cocci (except methicillin-resistant Staphylococcus, Enterococcus and Listeria), Staphylococcus aureus, Haemophilus influenzae, Escherichia coli and Proteus mirabilis. The mechanism of action is to inhibit bacterial cell wall synthesis.