학술논문

Off-Label Prescribing of Antiepileptic Drugs in Pharmacoresistant Epilepsy: A Cross-Sectional Drug Utilization Study of Tertiary Care Centers in Italy
Document Type
Academic Journal
Source
CNS Drugs. Oct 01, 2014 28(10):939-949
Subject
Language
English
ISSN
1172-7047
Abstract
PURPOSE: To assess the extent of off-label prescribing of antiepileptic drugs (AEDs) and associated variables in a large population of patients with pharmacoresistant epilepsy. METHODS: Descriptive analysis of data recorded from consecutively enrolled patients with pharmacoresistant epilepsy attending 11 tertiary referral centers in Italy. Offlabel use was stratified by therapeutic indication, dose, and age. Multivariate logistic regression was used to identify variables associated with off-label prescription. RESULTS: Of a total of 1,124 patients enrolled between November 2006 and August 2007, 53 % (101/191) of children and 31 % (287/933) of adults were receiving at least one off-label AED prescription. Among adults, offlabel use was related primarily to indication and was highest for clobazam (100 %) and ethosuximide (40 %), followed by lamotrigine (25 %), and vigabatrin (25 %). In children, clobazam (100 %), lamotrigine (79 %), vigabatrin (55 %), ethosuximide (46 %), and levetiracetam (43 %) were most frequently used off-label, with indication or age being the main causes depending on the specific AED. Logistic regression analysis indicated that higher rates of off-label use were associated with a polytherapy regimen (odds ratio [OR] 2.50, 95 % confidence interval [95 % CI], 1.55-4.03), pediatric age (2.49, 1.66-3.76), having failed ≥3 AEDs (2.16, 1.04-4.48), a diagnosis of generalized epilepsy with structural/metabolic or unknown etiology (2.97, 1.25-7.04), and increasing seizure frequency (1.07, 1.01-1.14). CONCLUSIONS: Off-label prescribing of AEDs is common among patients with pharmacoresistant epilepsy and is influenced by demographic and disease-related characteristics. Studies are needed to improve the quality of evidence guiding epilepsy treatment, and to evaluate the risks and benefits of off-label prescribing in epilepsy.