A photograph shows generalized, firm gingival enlargement (overgrowth) in a patient. Which medication is the most likely cause?

Phenytoin (an anticonvulsant) is a classic cause of drug-influenced gingival overgrowth, along with calcium channel blockers (e.g., nifedipine) and cyclosporine.Other options: Propranolol (beta-blocker), lorazepam (benzodiazepine), and clindamycin (antibiotic) are not associated with gingival enlargement.Key exam takeaway: Three classic drug classes causing gingival overgrowth: phenytoin, calcium channel blockers, and cyclosporine.