Concentrations of azithromycin in human tonsillar tissue

  • G. Foulds
  • K. H. Chan
  • J. T. Johnson
  • R. M. Shepard
  • R. B. Johnson


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 µg/g, respectively. Concurrent mean serum concentrations were approximately 0.03 and 0.01 µg/ml, respectively. The mean concentration in tonsillar tissue 7.5 days after the last dose was 0.93 µg/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.


Internal Medicine Serum Concentration Azithromycin Tonsillar Tissue Oral Azithromycin 
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Copyright information

© Friedr. Vieweg & Sohn Verlagsgesellschaft mbH 1991

Authors and Affiliations

  • G. Foulds
    • 1
  • K. H. Chan
    • 2
  • J. T. Johnson
    • 2
  • R. M. Shepard
    • 1
  • R. B. Johnson
    • 1
  1. 1.Central Research DivisionPfizer Inc.GrotonUSA
  2. 2.Department of OtolaryngologyUniversity of Pittsburgh School of MedicinePittsburghUSA

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