EFFECT OF DIPHENYLHYDANTOIN ON THE METABOLISM OF DICOUMAROL IN MAN

Abstract

Abstract. The effect of diphenylhydantoin on dicoumarol metabolism has been studied. Diphenylhydantoin decreases serum dicoumarol and increases prothrombin‐proconvertin concentration in patients receiving dicoumarol orally. The same effect was found when dicoumarol was given intravenously. The decrease in serum dicoumarol was evident after a few days of diphenylhydantoin treatment, but afteer withdrawal an increase in serum dicoumarol was not seen until 2–3 weeks later. Half‐lives of intravenously injected dicoumarol showed inconsistent changes following diphenylhydantoin treatment. Diphenylhydantoin probably acts by inducing the drug metabolizing enzyme system.