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.

It has a strong effect on most Gram-positive and Gram-negative bacteria, has good antibacterial effect on Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Shigella, and Salmonella, and has a good effect on some Staphylococci, gonococci, and meningococci. It has a weak effect on Streptococcus and Mycobacterium tuberculosis, and is ineffective against Pseudomonas aeruginosa and anaerobic bacteria. It is cross-resistant with kanamycin and has lower ototoxicity than kanamycin and gentamicin.

1. It has a positive inotropic effect on the myocardium, mainly acting on beta 1 receptors, and has relatively little effect on beta 2 and alpha receptors; 2. It can directly excite cardiac beta 1 receptors to enhance myocardial contraction and increase stroke volume, thereby increasing cardiac output; 3. It can reduce peripheral vascular resistance (reduced afterload), but systolic blood pressure and pulse pressure generally remain unchanged, or only increase due to increased cardiac output; 4. It can reduce ventricular filling pressure and promote atrioventricular node conduction; 5. Myocardial contractility is enhanced, and coronary blood flow and myocardial oxygen consumption often increase; 6. Due to increased cardiac output, renal blood flow and urine volume often increase; 7. Unlike dopamine, dobutamine does not act indirectly through the release of endogenous norepinephrine, but directly on the heart.

1. 5-HT3 receptor antagonism: The 5-HT3 receptor antagonism was shown in the 5-HT3 receptor contraction experiment in the guinea pig isolated colon and the Bezold-Jarisch reflex experiment in rats and ferrets. 2. Anti-tumor drug-induced vomiting inhibition: By blocking the 5-HT3 receptor, vomiting induced by anti-tumor drugs such as cisplatin can be inhibited.