TREATMENT PERSISTENCE WITH NEW ANTIEPILEPTIC DRUGS: LEVETIRACETAM, OXCARBAZEPINE, TOPIRAMATE, AND ZONISAMIDE
Abstract number :
2.256
Submission category :
Year :
2002
Submission ID :
1820
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Joyce A. Cramer, Grant Follansbee, James Vermilyea. Psychiatry, Yale University School of Medicine, New Haven, CT; Statistics, Aderis, Boston, MA
RATIONALE: At the end of this presentation, participants will be able to discuss the use of treatment persistence as a patient-reported treatment outcome. Treatment persistence is considered a global measure of the acceptability of treatment based on efficacy, adverse effects, and convenience. Four new antiepileptic drugs (AEDs) were compared using this global measure.
METHODS: Patients who started a new prescription for levetiracetam (N=766), oxcarbazepine (N=1208), topiramate (N=4544) or zonisamide (N=358) in January-February 2001 were followed for prescription refills for 12 months at a national retail pharmacy chain. Persistence was defined as time from the index prescription and the last month a prescription was filled. Kaplan-Meier analyses of days to discontinuation were based on use of less than 50% of prescribed doses, with Wilcoxon Chi Square tests between strata.
RESULTS: Mean treatment persistence rates were: levetiracetam 8.3[plusminus] 4.1 months, oxcarbazepine 7.3[plusminus]4.2 months, topiramate 8.0 [plusminus]4.1 months, and zonisamide 7.8[plusminus] 4.2 months. Levetiracetam persistence was significantly longer than oxcarbazepine for all patients and adjusting for age (both p[lt]0.0001). Kaplan Meier analyses (excluding zonisamide because of small numbers) also showed significantly longer time to discontinuation for levetiracetam than topiramate (p=0.018) and oxcarbazepine (p[lt]0.0001). Twelve-month discontinuation rates were significantly lower for levetiracetam than oxcarbazepine (p[lt]0.0001) and topiramate (p=0.0002).
CONCLUSIONS: These data demonstrate significant differences in treatment persistence for patients prescribed a new AED. In contrast to patients participating in clinical trials, this analysis represents long-term open use of new AEDs in a nationwide population. Continuation of the index AED suggests patient satisfaction with efficacy, tolerability, convenience or all aspects of treatment. Additional analyses will explore patterns of treatment crossover and use of concomitant AEDs.
[Supported by: UCB]; (Disclosure: Consulting - Elan, GlaxoSmithKline, Johnson & Johnson, Novartis, Pfizer, UCB, Honoraria - GlaxoSmithKline, Johnson & Johnson, Novartis, Pfizer, UCB)