This site is intended for healthcare professionals
Last reviewed dd mmm yyyy. Last edited dd mmm yyyy
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 Changes are most severe in the first year of treatment but can resolve if the drug is withdrawn.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.