A Fungal Story

Fatal Forty DDI: fluconazole, phenytoin, CYP2C9, CYP2C19


This cases discusses a pharmacokinetic interaction between phenytoin and fluconazole, resulting in phenytoin toxicity. Phenytoin is a cytochrome P450 2C9 and 2C19 substrate and fluconazole is a 2C9 and 2C19 inhibitor.


Pharmacokinetic Inhibitor Inhibition Phenytoin Dilantin CYP2C9 CYP2C19 Antibiotics Fluconazole Toxicity CYP Cytochrome P450 2C9 2C19 


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    Mamiya K, Ieiri I, Shimamoto J, et al. The effects of genetic polymorphism of CYP2C9 and CYP2C19 on phenytoin metabolism in Japanese adult patients with epilepsy: studies in stereoselective hydroxylation and population pharmacokinetics. Epilepsia. 1998;39(12):1317–23.PubMedCrossRefGoogle Scholar
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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Department of PharmacyOregon Health and Science UniversityPortlandUSA
  2. 2.Department of Anesthesiology and Perioperative MedicineOregon Health and Science UniversityPortlandUSA

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