Sinus fluid penetration of oral clarithromycin and azithromycin in patients with acute rhinosinusitis.

Background: The aim of this study was to investigate the extracellular concentration and the degree of sinus fluid penetration of newer macrolides, within the first 24-48 hours of treatment in patients with acute bacterial rhinosinusitis (ABRS), choosing clarithromycin and azithromycin as model antibiotics. An open, noninterventional pharmacokinetic study was performed at a tertiary teaching hospital.

Methods: In 36 outpatients with ABRS, sinus fluid aspirates and serum samples were collected 2, 4, 6, 8, and 12 hours or 2, 6, 12, and 24 hours after the administration of three doses of oral clarithromycin, 500 mg, twice daily or two doses of oral azithromycin, 500 mg, once daily, respectively.