title: Concentrations of azithromycin in human tonsillar tissue.
abstract: Patients scheduled to undergo tonsillectomy were administered 500 mg oral azithromycin as two 250 mg capsules given 12 h apart. Between 9 h and one week after the second dose, tonsil samples were taken during surgery and assayed for azithromycin. Mean concentrations in tonsillar tissue, 12 and 24 h after the second of the two 250 mg doses given 12 h apart, were 4.5 and 3.9 micrograms/g, respectively. Concurrent mean serum concentrations were approximately 0.03 and 0.01 micrograms/g, respectively. The mean concentration in tonsillar tissue 7.5 days after the last dose was 0.93 micrograms/g. The apparent half-life of drug in the tissue was 76 h. The ratio of mean concentration in tissue to that in serum was greater than 150-fold for all time intervals. The presence of high azithromycin concentrations in tonsillar tissue suggests that a once-daily regimen over five days or less may be effective in treating tonsillo-pharyngitis.
authors.affiliation: Central Research Division, Pfizer Inc., Groton, CT 06340.
authors.forename: G
authors.initials: G
authors.lastname: Foulds
authors.forename: K H
authors.initials: KH
authors.lastname: Chan
authors.forename: J T
authors.initials: JT
authors.lastname: Johnson
authors.forename: R M
authors.initials: RM
authors.lastname: Shepard
authors.forename: R B
authors.initials: RB
authors.lastname: Johnson
mesh_terms: D000284:Administration, Oral; D000328:Adult; D017963:Azithromycin; D002214:Capsules; D002908:Chronic Disease; D004334:Drug Administration Schedule; D004917:Erythromycin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000032:analysis / Q000493:pharmacokinetics; D006207:Half-Life; D006801:Humans; D008297:Male; D014066:Palatine Tonsil / Q000737:chemistry* / Q000378:metabolism; D013997:Time Factors; D014069:Tonsillitis / Q000378:metabolism
chemical_list: D002214:Capsules; D004917:Erythromycin; D017963:Azithromycin