Nitrendipine–Induced Gingival Overgrowth in Dogs

Abstract

This study assessed the development of gingival overgrowth in dogs given nitrendipine, a new antihypertensive dihydropyridine. Nine male Beagle dogs with established plaque and gingivitis were used. Following a baseline examination, which involved assessment of plaque, gingivitis, and gingival enlargement, six dogs (test) received nitrendipine twice daily in a high dose, while 3 dogs (control) received placebo. Clinical scorings were repeated after 10 and 20 weeks. At termination of the study gingival biopsies were excised and examined morphometrically. Already at the 10-week examination definite changes in gingival size had occurred, and following 20 weeks of nitrendipine treatment the gingival enlargement had markedly increased. In none of the control dogs were there any signs of gingival size changes. The histopathological examination showed that the only principal changes in histopathological morphology were that areas of non-infiltrated connective tissue in test specimens showed an increase in vascularity and appeared more loose compared with the dense tissue in control specimens. The morphometric analysis demonstrated minor differences between test and control specimens in regard to all tissue fractions observed; however, such differences were numerically very small, and were not considered biologically significant. Thus, the results demonstrated that nitrendipine administered to Beagle dogs during a 20-week period causes marked overgrowth of gingival tissue of apparently normal composition. The fact that cases of gingival overgrowth have been reported among patients receiving other dihydropyridines suggest that the observed gingival overgrowth is an effect of this class of drugs.

Tissue Distribution and Characterization of Drug-Related Material in Rats and Dogs after Repeated Oral Administration of Casopitant

“…This potential effect of DRM was supported by evidence of gingival changes seen in dogs during long-term study, a finding characteristic of some classes of calcium channel blockers in animals and humans (Heijl and Sundin, 1989;Ellis et al, 1999;Missouris et al, 2000). In vitro binding studies indicated a low calcium channel blockade by casopitant and M13, M12, and M31.…”

An Involvement of Granulocyte Medullasin in Phenytoin-Induced Gingival Overgrowth in Rats

“…However, the observed areas in their studies were buccal and lingual (not approximal), different from our areas (approximal). As stated above, gingival overgrowth occurs mostly in approximal areas, since bacterial plaque readily accumulates between teeth and can cause inflammation (16,24,25). Considering these, approximal gingival tissues could be more susceptible to gingival overgrowth due to the infiltration of inflammatory cells.…”

Gingival overgrowth and drug association

“…[15] Gingival overgrowth has been reported in 1-10% of the patients on calcium channel blockers. Ramon et al, 1984, [16] and Shaftic et al, 1986, [17] reported prevalence of overgrowth as 0.5-83% for nifedipine and 74% for diltiazem; whereas, Miller and Damm (1992) have observed 4% enlargement with verapamil therapy. [18] Some of the calcium channel blocker prescribed for different cardiovascular aliments are listed below and have been found to cause enlargement of gingiva.…”