A generalized seizure following initiation of nelfinavir in a patient with human immunodeficiency virus type 1 infection, suspected due to interaction between nelfinavir and phenytoin

Intern Med. 1999 Mar;38(3):302-3. doi: 10.2169/internalmedicine.38.302.


Nelfinavir, one of human immunodeficiency virus (HIV) specific protease inhibitors(PIs), is widely used for the treatment of HIV infection. Nelfinavir, which is metabolized with the cytochrome p450 isoforms, elevate the phenytoin level theoretically because nelfinavir acts as an inhibitor of phenytoin metabolism through the enzyme. However, we encountered a case of seizure recurrence caused by a lowered phenytoin level after initiation of nelfinavir. We should be aware of the change in the phenytoin level in concomitant use of nelfinavir.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anticonvulsants / pharmacokinetics
  • Anticonvulsants / therapeutic use*
  • Drug Interactions
  • Drug Therapy, Combination
  • Follow-Up Studies
  • HIV Infections / drug therapy*
  • HIV Protease Inhibitors / adverse effects*
  • HIV-1*
  • Humans
  • Male
  • Nelfinavir / adverse effects*
  • Phenytoin / pharmacokinetics
  • Phenytoin / therapeutic use*
  • Recurrence
  • Seizures / blood
  • Seizures / chemically induced*
  • Seizures / drug therapy


  • Anticonvulsants
  • HIV Protease Inhibitors
  • Phenytoin
  • Nelfinavir