Which adverse intraoral effect is associated with phenytoin, methotrexate, and calcium channel blockers?

• A. Gingival overgrowth
• B. Osteonecrosis
• C. Stomatitis & mucositis
• D. Candidiasis

Answer: (A)

Drug-induced gingival overgrowth is the adverse intraoral effect most associated with these medications. Phenytoin, a classic antiepileptic, stimulates gingival fibroblasts to produce more extracellular matrix, leading to collagen buildup and thickening of the gum tissue. This overgrowth is often worsened by plaque and inflammation. Calcium channel blockers such as nifedipine and other agents in this class produce a similar gingival fibroblast–driven response, with increased collagen synthesis and reduced degradation contributing to a fibrous, enlarged gingiva. Methotrexate can also affect the gingiva, and in some patients may contribute to gingival enlargement through effects on rapidly dividing cells and connective tissue metabolism, adding to the same overall pattern of tissue overgrowth.

The result is a noticeable gingival overgrowth that can obscure tooth margins and complicate oral hygiene. Other choices describe different oral effects more typical of these drugs in other contexts (stomatitis and mucositis from methotrexate toxicity; candidiasis as an opportunistic infection; osteonecrosis linked to other drugs), but the characteristic intraoral change tied to this specific drug combination is gingival overgrowth. In practice, management emphasizes meticulous plaque control, regular professional cleanings, and, if severe, surgical reduction or reconsideration of the offending medication when possible.