*2.6.3 Verapamil*

Verapamil is an effective preventive agent in both episodic and chronic cluster headache. Gingival overgrowth is an infrequent adverse effect of Verapamil and a prevalence rate of around 4.2% has been reported [33]. Histologically, verapamil induced gingival enlargement shows a highly vascular connective tissue, acanthotic and thickened epithelium with long rete pegs containing dyskeratotic pearls, and varying amounts of subepithelial inflammatory infiltrate which is similar to other group of drugs [65]. The histological appearance is similar to that caused by phenytoin, cyclosporin, and other calcium channel antagonists. Discontinuation of the drug usually results in complete regression of the gingival overgrowth.
