Cinazith/Cinazith-DS Mechanism of Action

Pharmacology: Azithromycin, a semisynthetic antibiotic belonging to the macrolide sub-group of Azalides, is used to treat STDs due to Chlamydia and gonorrhea, community-acquired pneumonia, pelvic inflammatory disease, pediatric otitis media and pharyngitis, and Mycobacterium avium complex (MAC) in patients with advanced HIV disease. Similar in structure to erythromycin, Azithromycin reaches higher intercellular concentrations than erythromycin, increasing its efficacy and duration of action.
Mechanism of Action: Azithromycin binds to the 50S subunit of the 70S bacterial ribosomes, and therefore inhibits RNA-dependent protein synthesis in bacterial cells.
Pharmacokinetics: Azithromycin given orally is about 40% bioavailable. Absorption from capsules, but not tablets, is reduced by food.
Peak plasma concentrations are achieved 2 to 3 hours after a dose, but Azithromycin is extensively distributed to the tissues, and tissue concentrations subsequently remain much higher than those in the blood; in contrast to most other antibacterials, plasma concentrations are therefore of little value as a guide to efficacy. High concentrations are taken up into white blood cells. There is little diffusion into the CSF when the meninges are not inflamed. Small amount of Azithromycin are demethylated in the liver, and it is excreted in bile as unchanged drug and metabolites.
For prevention of Mycobacterium avium complex (MAC) disease.
Following oral administration in human, Azithromycin is widely distributed throughout the body; bioavailability is approximately 40%.
No significant decrease in bioavailability was observed when Azithromycin tablets were administered with a meal. The time taken to peak plasma levels is 2-3 hours. Plasma terminal elimination half-life closely reflects the tissue depletion half-life of 2 to 4 days.