It acts on dihydrofolate synthase, interfering with the first step of folic acid synthesis. When used in combination with trimethoprim, it can doubly block the bacterial folic acid metabolism and has a synergistic antibacterial effect.

It acts on the second step of folic acid anabolism, selectively inhibits the action of dihydrofolate reductase, and when used in combination with sulfadiazine, it can double-block the bacterial folic acid metabolism and has a synergistic antibacterial effect.

It has a good antibacterial effect on human tuberculosis bacteria, and its bactericidal effect is strongest at pH 5-5.5. It is currently the best bactericidal drug for tuberculosis bacteria that grow slowly in phagocytes in an acidic environment. The antibacterial concentration in vivo is 12.5μg/ml, and 50μg/ml can kill tuberculosis bacteria. The concentration that inhibits tuberculosis bacteria inside cells is 10 times lower than that outside cells, and it has almost no antibacterial effect in neutral and alkaline environments. The mechanism of action may be related to pyrazinoic acid. After pyrazinamide penetrates into phagocytes and enters the tuberculosis bacteria, the amidase in the bacteria removes the amide group and converts it into pyrazinoic acid to exert an antibacterial effect. In addition, because pyrazinamide is similar to nicotinamide in chemical structure, it interferes with dehydrogenase by replacing nicotinamide, prevents dehydrogenation, and hinders the use of oxygen by tuberculosis bacteria, which affects the normal metabolism of bacteria and causes death.

Sulfonylurea is an oral hypoglycemic diabetes treatment drug. It lowers blood sugar levels by stimulating pancreatic β cells to secrete insulin, restores the peak of first-phase insulin secretion in response to glucose and increases first-phase insulin secretion. The insulin secretion response induced or stimulated by glucose after a meal is significantly increased. At the same time, it reduces the microthrombosis process by partially inhibiting platelet adhesion and aggregation and producing fibrinolytic activity on the vascular endothelium.

It selectively inhibits succinate dehydrogenase in the muscles of the worm, affects the anaerobic metabolism of the worm muscles, and reduces energy production; it depolarizes the nerve muscles, causing continuous muscle contraction and paralysis; its cholinergic effect is beneficial to the excretion of the worm; it may have an inhibitory effect on the microtubule structure of the worm; it has immune regulation and immune excitation functions.

This product has a broad-spectrum antibacterial effect, especially high antibacterial activity against aerobic Gram-negative bacilli. It has good antibacterial activity in vitro against the following bacteria: most bacteria of the Enterobacteriaceae family, including Citrobacter, cloacae, Enterobacter aerogenes, Escherichia coli, Klebsiella, Proteus, Salmonella, Shigella, Vibrio, Yersinia, etc. It often has antibacterial activity against multi-drug resistant bacteria. It has high antibacterial activity against penicillin-resistant Neisseria gonorrhoeae, enzyme-producing Haemophilus influenzae and Moraxella. It has antibacterial activity against most strains of Pseudomonas such as Pseudomonas aeruginosa. This product has antibacterial activity against methicillin-sensitive Staphylococcus, and only moderate antibacterial activity against Streptococcus pneumoniae, hemolytic Streptococcus and Enterococcus faecalis. It also has good effects on Chlamydia trachomatis, Mycoplasma, Legionella, and antibacterial activity against Mycobacterium tuberculosis and atypical mycobacteria. Poor antibacterial activity against anaerobic bacteria. Ciprofloxacin is a bactericide that acts on the A subunit of bacterial DNA gyrase, inhibiting DNA synthesis and replication, leading to bacterial death.