Prevalence and risk of gingival overgrowth in patients treated with diltiazem or verapamil

Objectives: This study was conducted to determine the prevalence and risk factors for gingival enlargement in patients treated with diltiazem or verapamil. Material and Methods: A cross-sectional study was conducted and data from 46 patients actually taking diltiazem or verapamil were compared with 49 cardiovascular controls that never received any of these drugs. All patients were examined for the presence of gingival enlargement using two different indices, the vertical gingival overgrowth (GO) index, and horizontal Miranda & Brunet (MB) index in the inter-dental area. Gingival index, plaque index, and probing depth were also evaluated. Results: The total study population was 95:32 diltiazem-treated, 14 verapamil-treated and 49 cardiovascular control subjects. Gingival enlargement occurred in 31% (GO index) and 50% (MB index) of the patients taking diltiazem. Gingival enlargement in the verapamil-treated group was 21% for the GO index and 36% for the MB index. The prevalence of gingival enlargement was higher in the diltiazem- and verapamil-treated patients than in controls for both indices. The difference between the diltiazem-treated group and control was statistically significant (p=0.022 for GO and p=0.001 for MB), while the difference between the verapamil-treated group and controls was not significant. The risk of gingival enlargement (OR - Odds Ratio) associated with diltiazem therapy was 4.0 (1.2-13.1) for the GO index and of 6.0 (2.1-17.3) for the MB index. When the OR were adjusted for gingival index (GI) values, the risk of gingival enlargement was 3.5 (1.0-12.4) for the GO index and 6.2 (1.9-20.0) for the MB index. In the verapamil-treated group the OR values were not significant. The level of concordance between GO and MB indices in all three groups showed a kappa-value of 0.72 (p < 0.001). Conclusion: Patients taking diltiazem are at high risk for gingival enlargement and gingivitis has a stronger effect than the drug treatment on gingival enlargement risk.