title: Drug concentration in inflamed periodontal tissues after systemically administered azithromycin.
abstract: BACKGROUND
  Azithromycin is an azalide antibiotic, effective against a wide range of oral bacteria including periodontopathic bacteria. Azithromycin is taken up by phagocytes and is released into inflamed tissue over time. The concentration of azithromycin in inflamed periodontal tissues over time has not been studied. In this study, we determined the azithromycin concentration in the gingiva and inflammatory connective tissue of the periodontal pocket in periodontal patients who had been administered azithromycin systemically. We also evaluated the clinical and microbiologic effects of azithromycin.
  
  
  METHODS
  Thirty-four patients with periodontitis were prescribed azithromycin 500 mg once daily for 3 days. During the 14-day study, clinical parameters (probing depth, gingival index, bleeding on probing, and gingival crevicular fluid level) were recorded, subgingival plaque was collected for bacteriologic examination, and the azithromycin concentration in the tissues lining the periodontal pocket was measured by agar diffusion bioassay.
  
  
  RESULTS
  Clinical parameters significantly improved after administration of azithromycin. The total number of cultivated bacteria also significantly decreased by day 4 but slightly increased after day 7. Sustained reduction in levels of six periodontopathic bacteria was not apparent until day 14. On day 7, the azithromycin concentration in the tissues lining the periodontal pockets was 50% of that on day 4, and on day 14 only 20%.
  
  
  CONCLUSIONS
  Azithromycin is detectable in inflamed periodontal tissues >or=14 days after systemic administration; it is associated with clinical and microbiologic improvement.
authors.affiliation: Department of Periodontics and Endodontics, Tsurumi University, School of Dental Medicine, Yokohama, Japan. gomi-k@tsurumi-u.ac.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Gomi
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yashima
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Iino
authors.forename: Mikimoto
authors.initials: M
authors.lastname: Kanazashi
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Nagano
authors.forename: Naoya
authors.initials: N
authors.lastname: Shibukawa
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ohshima
authors.forename: Nobuko
authors.initials: N
authors.lastname: Maeda
authors.forename: Takashi
authors.initials: T
authors.lastname: Arai
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D017963:Azithromycin / Q000493:pharmacokinetics*; D003238:Connective Tissue / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010514:Periodontal Pocket / Q000188:drug therapy / Q000378:metabolism* / Q000382:microbiology; D010519:Periodontium / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin