Distribution of systemic clarithromycin to gingiva

Abstract

Background: Aggressive and recurrent forms of periodontitis are associated with infections by Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) and Porphyromonas gingivalis. Because these pathogens invade tissue, they are difficult to eliminate by root planing alone. The use of systemic antibiotics in conjunction with root planing significantly enhances clinical and microbiologic treatment outcomes. Although it is not widely prescribed by periodontists, clarithromycin is potentially useful because it is taken up by host cells and has favorable antimicrobial activity.

Methods: Experimental gingivitis was induced in eight healthy subjects at one randomly selected maxillary posterior site. The contralateral maxillary site served as the healthy control. Thereafter, subjects were administered six doses of clarithromycin, 500 mg, every 12 hours. Blood was then drawn, and samples of gingiva were harvested from both sites. The samples were extracted, and clarithromycin content was analyzed by liquid chromatography.

Results: Mean clarithromycin concentrations in healthy control and inflamed gingiva (2.4 and 3.0 microg/g, respectively) were significantly higher than in serum (0.5 microg/ml; P <0.05). Clarithromycin levels at control and gingivitis sites were higher than serum by 5.7- and 7.0-fold, respectively (difference between sites was significant; P = 0.02). At control sites, a significant decrease in gingival crevicular fluid flow rate was evident at the conclusion of the clarithromycin regimen (P = 0.018).

Conclusions: Clarithromycin can attain higher levels in gingiva than serum and reach higher levels in inflamed gingiva than in healthy gingiva. Its distribution profile seems to be suitable for the treatment of periodontitis. The reduction in crevicular fluid flow at control sites suggested that clarithromycin may produce anti-inflammatory effects.