It has a direct relaxant effect on the smooth muscles of the respiratory tract, partially achieving bronchial dilation by releasing endogenous adrenaline and norepinephrine. At the same time, it acts as a purine receptor blocker to counteract the contractile effect of adenine and other substances on the respiratory tract, thereby enhancing the contractility of the diaphragm to improve respiratory function.

It increases the water solubility of aminophylline and indirectly participates in improving respiratory function.

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 has a significant inhibitory effect on gastric acid secretion and can also inhibit the secretion of pepsin

It is a semi-synthetic broad-spectrum penicillin antibiotic that mainly acts on the bacterial reproduction stage by inhibiting the biosynthesis of cell wall mucopolypeptides. It is effective against many Gram-positive and Gram-negative bacteria.

It has a β-lactam structure similar to penicillin and has only weak antibacterial activity itself, but it can inactivate enzymes produced by many bacteria by blocking the active site of β-lactamase, especially for clinically important plasmid-mediated β-lactamase. It can protect amoxicillin from hydrolysis and destruction by β-lactamase, so it is still effective against resistant bacteria that produce β-lactamase.