Description
Mechanism of Action
Azithromycin is a semisynthetic azalide antibiotic. It blocks transpeptidation by binding to 50s ribosomal subunit of susceptible organisms and disrupting RNA-dependent protein synthesis at the chain elongation step.
Absorption: Rapidly absorbed from the GI tract. Reduced by food (capsule formulation). Absolute bioavailability: Approx 34-52%. Time to peak plasma concentration: Oral tab: 2-3 hr; IV: 1-2 hr.
Distribution: Extensive into the tissues (higher than those in blood), WBC (high concentrations), CSF (small amounts). Volume of distribution: 31-33 L/kg. Plasma protein binding (concentration dependent): 7-51% (oral and IV).
Metabolism: Hepatic metabolism via demethylation.
Excretion: Via bile (as unchanged drug and inactive metabolites); urine (approx 6% of oral dose). Terminal elimination half-life: About 68 hr.
MIMS Class
Macrolides
ATC Classification
J01FA10 – azithromycin; Belongs to the class of macrolides. Used in the systemic treatment of infections.;
S01AA26 – azithromycin; Belongs to the class of antibiotics. Used in the treatment of eye infections.;
