Azithromycin is a 15-membered macrolide antibiotic. In vitro tests have shown that azithromycin has antibacterial effects on a variety of common clinical pathogens, including: Gram-positive aerobic bacteria, Staphylococcus aureus, Streptococcus pyogenes (group A beta; hemolytic streptococci), pneumonia (streptococci), a-hemolytic streptococci (grass-green streptococci) and other streptococci, diphtheria (rod-shaped) bacilli. This product shows cross-resistance to erythromycin-resistant Gram-positive bacteria, including fecal streptococci (enterococci) and various methicillin-resistant Staphylococcus strains.

The pharmacological effects extracted from the above information are not clearly described

1. Calcium ion antagonist, regulating calcium ion influx on the cell membrane of myocardial conduction cells, myocardial contractile cells and arterial smooth muscle cells, but does not change serum calcium concentration. 2. Dilates the main coronary artery and arterioles, antagonizes coronary artery spasm, increases myocardial oxygen delivery, reduces myocardial oxygen consumption, and is used to treat variant angina and unstable angina. 3. Prolongs the effective refractory period of the atrioventricular node, slows conduction, reduces the ventricular rate of patients with chronic atrial fibrillation and atrial flutter, and reduces the frequency of paroxysmal supraventricular tachycardia. 4. It produces a hypotensive effect by reducing systemic vascular resistance, and generally does not cause postural hypotension or reflex tachycardia. 5. Reduces afterload, inhibits myocardial contraction, and improves left ventricular diastolic function. 6. Animal experiments show that it has a local anesthetic effect, but the specific human effect and dosage are still unclear.

This product can cause blood vessels to contract, reduce capillary permeability, enhance platelet aggregation and adhesion, promote platelets to release coagulation active substances, shorten coagulation time, and achieve hemostatic effect.

Nucleoside antiviral drugs. Competitively inhibit DNA polymerase and incorporate into the DNA of viruses and host cells, thereby inhibiting DNA synthesis. The inhibitory effect on viral DNA polymerase is stronger than that on host cell polymerase. In animal experiments, this product has teratogenic, carcinogenic, immunosuppressive effects and reproductive system toxicity.