Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Interaction between valproate formulation and phenytoin concentrations

Y Suzuki1, T Nagai, T Mano

  • 1Department of Pediatrics, Osaka University Medical School, Japan.

European Journal of Clinical Pharmacology
|January 1, 1995
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Adult-onset spinocerebellar dysfunction caused by a mutation in the gene for the alpha-tocopherol-transfer protein.

The New England journal of medicine·1995
Same author

Tau in cerebrospinal fluid: a potential diagnostic marker in Alzheimer's disease.

Annals of neurology·1995
Same author

Purification and characterization of platelet-activating factor acetylhydrolase II from bovine liver cytosol.

The Journal of biological chemistry·1995
Same author

cDNA cloning of human cytosolic platelet-activating factor acetylhydrolase gamma-subunit and its mRNA expression in human tissues.

Biochemical and biophysical research communications·1995
Same author

Response of human gingival fibroblasts to prostaglandins.

Journal of periodontal research·1995
Same author

Hemorheological and hemodynamic analysis of hypervolemic hemodilution therapy for cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

Stroke·1995

Switching valproate formulations significantly increased phenytoin levels in epileptic patients. This change in medication can alter drug concentrations, potentially leading to toxicity.

Area of Science:

  • Pharmacology
  • Clinical Pharmacy
  • Epilepsy Management

Background:

  • Phenytoin and valproate are commonly prescribed antiepileptic drugs.
  • Valproate is available in various formulations with differing absorption rates.
  • Drug interactions can affect plasma concentrations of co-administered medications.

Purpose of the Study:

  • To investigate the impact of switching valproate formulations on phenytoin plasma concentrations.
  • To assess the clinical significance of altered phenytoin levels in patients on combined therapy.

Main Methods:

  • Retrospective analysis of eleven epileptic patients on both phenytoin and valproate.
  • Measurement of total plasma phenytoin concentrations before and after switching valproate formulation.
  • Comparison of standard valproate tablets to slow-release valproate tablets.

Related Experiment Videos

Main Results:

  • Mean plasma phenytoin levels increased significantly from 14.4 to 18.7 µg/mL.
  • Nine out of eleven patients experienced marked increases in phenytoin levels (21-72%).
  • Two patients developed phenytoin toxicity symptoms.

Conclusions:

  • Changing valproate formulations can significantly alter co-administered phenytoin plasma concentrations.
  • Close monitoring of phenytoin levels is crucial when switching valproate formulations.
  • This interaction highlights the importance of considering drug formulation in polytherapy.