A double-blind placebo-controlled trial of azithromycin as an adjunct to non-surgical treatment of periodontitis in adults: clinical results

Abstract

Background/aims: The aim of the study was to investigate the clinical and microbiological effects of azithromycin as an adjunct to the non-surgical treatment of periodontitis in adults. Azithromycin is an antibiotic which is taken up by phagocytes and is released over long periods in inflamed tissue but requires a total of only three doses of 500 mg to produce its therapeutic effect.

Method: 46 patients were treated in a double-blind placebo-controlled study with assessments at weeks 0, 1, 2, 3, 6, 10 and 22. Throughout the trial measurements were made of plaque, gingival bleeding, calculus, probing pocket depths and bleeding on probing. Microbiological sampling was carried out from a selected pocket >or=6 mm at each visit. The regime employed consisted of OHI, scaling and root planing at weeks 0, 1 and 2 with reinforcement of OHI and minimal scaling at weeks 6, 10 and 22. Patients were randomly assigned to receive either azithromycin, (A), or placebo capsules, (C), 500 mg, 1x daily for 3 days at week 2. 44 patients completed the study. Mean pocket depths were analysed using analysis of covariance in 3 groups with initial pocket depth values of 1-3 mm, 4-5 mm and >or=6 mm.

Results: The results of the microbiology have been reported in a separate paper. The clinical data showed that by week 22 a lower % of pockets initially >5 mm deep remained above that level in the 23 patients taking azithromycin (A), than the 21 taking the placebo (C), (A, 5.6%; C, 23.3%). Also at week 22, for pockets initially 4 mm or more, the test group had fewer pockets >3 mm deep (A, 26.1%; C, 44.3%), fewer failing to improve in probing depth (A, 6.6%; C, 21.6%) and fewer continuing to bleed on probing (A, 46.9%; C, 55.6%) when compared with the control group. Pocket depths initially 4-5 mm or 6-9 mm analysed by analysis of covariance showed lower mean pocket depths in the patients on azithromycin, at weeks 6, 10 and 22, (pockets initially 4-5 mm, p<0.001 on all occasions, pockets initially 6-9 mm, p<0.001, week 6; p< 0.003, week 10; p<0.001, week 22).

Conclusions: Azithromycin may be a useful adjunct in the treatment of adult periodontitis, particularly where deep pockets are present.