Azithromycin (Zithromax®, Pfizer, Inc., New York, NY) is a 15-membered-ring macrolide and
the first azalide antibiotic. It is distinguished from other macrolides by its rapid and extensive
penetration into intracellular and interstitial tissue compartments, accompanied by prolonged
tissue and serum half-lives. Azithromycin shares the gram-positive activity of erythromycin but
is more potent against gram-negative organisms. For urethritis and cervicitis caused by
Chlamydia trachomatis, azithromycin is effective and well tolerated in a single dose of 1 g, a regimen
recommended by the CDC. A 5-day dosage regimen is available for the treatment of community-acquired
respiratory-tract and skin and skin-structure infections caused by susceptible organisms.
Azithromycin provides short-duration, high-compliance, cost-effective regimens that should improve
outcomes.
