Abstracts

Rapid Development of Lamotrigine Encephalopathy Precipitated by Introduction of Low Dose Valproate.

Abstract number : 3.122
Submission category :
Year : 2001
Submission ID : 331
Source : www.aesnet.org
Presentation date : 12/1/2001 12:00:00 AM
Published date : Dec 1, 2001, 06:00 AM

Authors :
N.A. Limdi, Pharm.D, Pharmacy, University of Alabama at Birmingham, Birmingham, AL; E.R. Faught, M.D., Neurology, University of Alabama at Birmingham, Birmingham, AL; T. Welty, Pharm.D, Pharmacy, Samford University, Birmingham, AL; N. Lawn, MD, Neurology,

RATIONALE: The metabolism of lamotrigine is strongly inhibited by valproate. We report two cases of encephalopahty assocaited with lamotrigine caused by the the introduction of low doses of valproate.
METHODS: Two patients on lamotrigine monotherapy, with a recent history of addition of valproate presented with neurological signs and symptoms within one week of begining oral valproate.
RESULTS: Patient 1 was a 31 year old woman who was confused and responded inappropriately. Diffuse slow waves were present on her EEG. Patient 2 was a 48 year old woman who complained of frequent falls, a drunken feeling, blurred vision and slowed speech[table]
CONCLUSIONS: Initiation of valproate therapy even at 500mg/day can precipitously increase lamotrigine levels which may result in encephalopahty with features of cortical and cerebellar dysfunction.
Support: No external funding support.
Disclosure: Grant - Both Nita Limdi and Edward Faught have received research grants (un-related to this project) from Abbott Laboratories; Honoraria - Both Nita Limdi and Edward Faught have received honoraria for speaking from Abbott Laboratories. Dr Faught has also received honoraria for speaking for Glaxo.