Azithromycin

Absorption	Bioavailability is 37% following oral administration. Absorption is not affected by food. Azithromycin is extensively distributed in tissues with tissue concentrations reaching up to 50 times greater than plasma concentrations. Drug becomes concentrated within macrophages and polymorphonucleocytes giving it good activity against Chlamydia trachomatis.
Volume of distribution	31.1 L/kg
Protein binding	Serum protein binding is variable in the concentration range approximating human exposure, decreasing from 51% at 0.02 µg/mL to 7% at 2 µg/mL.
Metabolism	Hepatic. In vitro and in vivo studies to assess the metabolism of azithromycin have not been performed.
Route of elimination	Biliary excretion of azithromycin, predominantly as unchanged drug, is a major route of elimination.
Half life	68 hours
Clearance	apparent plasma cl=630 mL/min [following single 500 mg oral and i.v. doses]
Toxicity	Potentially serious side effects of angioedema and cholestatic jaundice were reported
Affected organisms	Enteric bacteria and other eubacteria