1. Increase the effect of anticoagulants; 2. Increase the level of phenytoin sodium in the blood; 3. The metabolism is accelerated by anticonvulsants (such as carbamazepine and phenytoin sodium), which can displace thyroxine from plasma proteins; 4. The dosage of cardiac glycosides needs to be adjusted when used with cardiac glycosides; 5. Increase the effect of sympathomimetic drugs; 6. Increase the sensitivity of catecholamine receptors, thereby increasing the response of tricyclic antidepressants; 7. The absorption is reduced by the influence of cholestyramine, and the dosage of levothyroxine sodium needs to be increased when used with oral contraceptives.

Quinolone antibacterial drugs inhibit bacterial DNA helicase and have a broad-spectrum antibacterial effect. They have strong antibacterial activity against Enterobacter bacteria such as Escherichia coli, Klebsiella, Proteus, Shigella, Salmonella typhi, etc., as well as influenza bacillus and Neisseria. They also have certain antibacterial effects on Staphylococcus aureus and Pseudomonas aeruginosa. They have only mild effects on pneumococci, various groups of streptococci and enterococci.

Quinolone antibacterial drugs inhibit bacterial DNA helicase and have a broad-spectrum antibacterial effect. They have strong antibacterial activity against Enterobacter bacteria such as Escherichia coli, Klebsiella, Proteus, Shigella, Salmonella typhi, etc., as well as influenza bacillus and Neisseria. They also have certain antibacterial effects on Staphylococcus aureus and Pseudomonas aeruginosa. They have only mild effects on pneumococci, various groups of streptococci and enterococci.

It has a broad-spectrum antibacterial effect, especially high antibacterial activity against aerobic Gram-negative bacteria, and has antibacterial activity against most bacteria of the Enterobacteriaceae family, penicillin-resistant Neisseria gonorrhoeae, enzyme-producing influenza bacilli and Moraxella, Pseudomonas aeruginosa, etc. It has antibacterial activity against methicillin-sensitive Staphylococci, and only moderate antibacterial activity against Streptococcus pneumoniae, hemolytic Streptococcus, and Enterococcus faecalis. It has good antimicrobial effects against Chlamydia trachomatis, Mycoplasma, and Legionella, and also has antibacterial activity against Mycobacterium tuberculosis and atypical mycobacteria. It has poor antibacterial activity against anaerobic bacteria. Ciprofloxacin is a bactericide that acts on the A subunit of bacterial DNA helicase, inhibiting DNA synthesis and replication, leading to bacterial death.