Abstracts

Outcomes of Switch Therapy in Seizure Patients: Divalproex Sodium to Lamotrigine.

Abstract number : 2.239
Submission category :
Year : 2001
Submission ID : 904
Source : www.aesnet.org
Presentation date : 12/1/2001 12:00:00 AM
Published date : Dec 1, 2001, 06:00 AM

Authors :
J.C. Dean, MD, Epilepsy Institute of North Carolina, Winston-Salem, NC; L.M. Muraoka, BSPharm, MS, Abbott Laboratories, Abbott Park, IL; T.H. Wiser, BS, PharmD, Abbott Laboratories, Abbott Park, IL; K.W. Sommerville, MD, Abbott Laboratories, Abbott Park,

RATIONALE: The study objective is to document the patient outcomes in patients undergoing switch therapy. Availability of numerous newer medications to the antiepileptic therapeutic armamentarium have increased the available choices to providers to treat patients with epilepsy. Reports have suggested that lamotrigine (LTG) may have utility in patients with generalized epilepsy associated with myoclonic seizures. This descriptive study analysis shows consecutive data collected over a 5-year period in patients with generalized epilepsy who were converted from divalproex sodium (DVPX) to LTG monotherapy.
METHODS: Data were analyzed from retrospective chart reviews in all outpatients with generalized epilepsy (n=2468) seen from August 1996 to August 2000. All patients with generalized epilepsy, including generalized tonic-clonic seizures (GTCS), absence seizures (AS), juvenile myoclonic epilepsy (JME), myoclonic seizures, and atonic seizures, who were controlled with DVPX monotherapy but experienced adverse events associated with DVPX were switched to LTG. Three-hundred forty patients (129, male; 211, female), aged 16-48 years (mean-26 years) with generalized epilepsy were converted from DVPX to LTG monotherapy over a 12-week period. These patients were slowly titrated upward with LTG (200 mg/day) over a 6-week period while maintaining DVPX (10-20 mg/kg/day) at a constant dose. At week 6, DVPX taper was initiated over a 6-week period while maintaining LTG therapy (200 mg/day). At week 8, LTG was increased to 250 mg/day. At week 12, these patients were converted to LTG monotherapy (300 mg/day). Compliance was monitored by formal drug history, medication count, serum concentration monitoring, and prevalence of seizures post-conversion.
RESULTS: Two-hundred two (59%) of 340 patients with generalized seizures failed successful conversion to LTG monotherapy. Of the 202 patients who failed therapy, 120 (59%) patients had JME, 72 (36%) patients had GTCS, 6 (3%) patients had AS, and 4 (2%) patients had myoclonic jerks. Of the 138 patients who were successfully converted to LTG monotherapy, 98 (71%) patients had GTCS.
CONCLUSIONS: The primary conclusion of this study suggests that patients with primary myoclonic presentation of JME may not be adequately controlled with LTG monotherapy. However, further controlled studies are needed to confirm this finding. Careful consideration of switch therapy in patients with epilepsy who are adequately controlled must be exercised with extreme caution.
Support: This study was supported by Abbott Laboratories.
Disclosure: Other - Employees of Abbott Laboratories: LM Muraoka, TH Wiser, KW Sommerville