Trial of metronidazole vs. azithromycin for treatment of cyclosporine-induced gingival overgrowth

Gingival overgrowth usually characterized by increased cellular growth of gingival fibroblasts appears to be multifactorial. In patients receiving CyA for more than 3 months, the incidence can approach 70% and can be attributed to pharmaceutical immunosuppression. Case reports have reported regression of overgrowth with both metronidazole and azithromycin. The goal of this study was to determine the efficacy of metronidazole and azithromycin in reducing CyA-induced gingival overgrowth. Twenty-five patients were included in this double-blinded randomized study. All patients were receiving CyA as medically indicated and diagnosed with gingival overgrowth by a dentist. Patients were randomized to receive either 5-days of azithromycin or 7-days of metronidazole given at baseline only. The extent of gingival overgrowth was measured at 0, 2, 4, 6, 12, and 24 wk. Fourteen patients at CCF and 11 patients at CCHMC were studied. Repeated measures ANOVA was performed to assess differences within and between groups. Gingival overgrowth at baseline was not statistically different between groups. The mean degree of gingival overgrowth after treatment was different across all time intervals (p = 0.0049) showing azithromycin to be more effective than metronidazole. Therapy with azithromycin offers an effective alternative to the management of CyA-induced gingival overgrowth.