gingival hypertrophy secondary to phenytoin

Last reviewed 01/2018

Gingival overgrowth occurs in roughly half of the patients taking phenytoin. Changes are most severe in the first year of treatment but can resolve if the drug is withdrawn. Poor oral hygiene exacerbates the effect.

It is hypothesised that plaque causes inflammation with an increased turnover of connective tissue, phenytoin inhibits cellular folate uptake and the folate-depleted cells cannot enzymes to break down the excess of connective tissue.

Management entails:

  • scrupulous oral hygiene:
    • counsel the patient beforehand about the requirement for regular and thorough brushing
    • chlorhexidine mouthwash may be used prophylactically
  • oral folic acid has been found to decrease the incidence of phenytoin induced gingival overgrowth in children on phenytoin monotherapy
  • treat established overgrowth:
    • surgical excision until aesthetic improvement
    • change of anticonvulsant if overgrowth is severe and persistent


  • Seymour, R.A.. Phenytoin and gingival overgrowth. Prescribers' Journal 1992;32(3): 124-126.
  • Arya R et al. Folic acid supplementation prevents phenytoin-induced gingival overgrowth in children.Neurology. 2011 Apr 12;76(15):1338-43.