Dyskinesia during concomitant usage of phenytoin and capecitabine

Correspondence to Dinesh Keerty, Department of Internal Medicine, Moffitt Cancer Center, 12902 USF Magnolia Drive, Tampa, FL 33602, USA; dinesh.keerty@gmail.com INTRODUCTION Phenytoin is an anticonvulsant used for prevention of tonic–clonic and partial seizures via blockage of voltage-gated sodium channels. Decreasing phenytoin level DISCUSSION Metabolism of phenytoin is by the hepatic cytochrome P450 enzymes, CYP2C9 and CYP2C19. 2 The metabolism of phenytoin is saturable, making it highly susceptible to drug interactions. Contributors DK: provided the design of the work, analysis of data, drafting the work for important intellectual content and had done final approval of the version published and accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.