LeLorier Jacques, Duh Mei Sheng, Paradis Pierre Emmanuel, Latrémouille-Viau Dominick, Lefebvre Patrick, Manjunath Ranjani, Sheehy Odile
Centre de recherche, Centre hospitalier de l'Université de Montréal, Québec, Canada.
Curr Med Res Opin. 2008 Apr;24(4):1069-81. doi: 10.1185/030079908x280572. Epub 2008 Feb 29.
Generic substitution may not always save health care costs for antiepileptic drugs (AED).
(1) To examine the economic impacts of generic substitution of lamotrigine in Canada; and (2) to convert observed Canadian costs to a United States (US) setting.
Health claims from Québec's health plan (RAMQ) between 08/2002 and 07/2006 were analyzed. Patients with > or = 1 epilepsy claim and treated with branded lamotrigine (Lamictal) before generic entry were selected. Health care costs ($/person-year) were compared during periods of branded and generic use of lamotrigine. Two cost-conversion methods were employed; one using purchasing power parities, US/Canada service use ratios, and exchange rate, and another employing Canadian health care utilization and US unit costs.
671 patients were observed during 1650.9 and 291.2 person-years of branded and generic use of lamotrigine, respectively. The generic-use period was associated with an increase in overall costs (2006 constant Canadian dollars) relative to brand use (C$7902 vs. C$6419/person-year; cost ratio (CR) = 1.22; p = 0.05), despite the lower cost of generic lamotrigine. Non-lamotrigine costs were 33% higher in the generic period (p = 0.013). Both conversion methods yielded increases in total projected health care costs excluding lamotrigine (2006 constant US dollars) during the generic period (Method 1: cost difference: US$1758/person-year, CR = 1.33, p = 0.01); Method 2: cost difference: US$2516, CR = 1.39, p = 0.004).
Study limitations pertain to treatment differences, indicators used for conversion and possible claim inaccuracies.
Use of generic lamotrigine in Canada was significantly associated with increased overall medical costs compared to brand use. Projected overall US health care costs would likely increase as well.
通用名药物替代并不总是能节省抗癫痫药物（AED）的医疗费用。
（1）研究加拿大拉莫三嗪通用名药物替代的经济影响；（2）将观察到的加拿大成本换算为美国的情况。
分析了魁北克省医疗计划（RAMQ）在2002年8月至2006年7月期间的健康索赔数据。选择了在通用名药物上市前有≥1次癫痫索赔且接受品牌拉莫三嗪（利必通）治疗的患者。比较了拉莫三嗪品牌药使用期和通用名药使用期的医疗费用（美元/人年）。采用了两种成本换算方法；一种使用购买力平价、美国/加拿大服务使用比率和汇率，另一种采用加拿大医疗保健利用率和美国单位成本。
分别在1650.9和291.2人年的拉莫三嗪品牌药使用期和通用名药使用期观察了671名患者。尽管通用名拉莫三嗪成本较低，但与品牌药使用期相比，通用名药使用期的总体成本（2006年不变加拿大元）有所增加（7902加元/人年对6419加元/人年；成本比（CR）=1.22；p = 0.05）。通用名药使用期的非拉莫三嗪成本高出33%（p = 0.013）。两种换算方法均显示，在通用名药使用期，不包括拉莫三嗪的预计医疗总费用（2006年不变美元）有所增加（方法1：成本差异：1758美元/人年，CR = 1.33，p = 0.01）；方法2：成本差异：2516美元，CR = 1.39，p = 0.004）。
研究局限性涉及治疗差异、用于换算的指标以及可能的索赔不准确。
与品牌药使用相比，加拿大通用名拉莫三嗪的使用与总体医疗成本增加显著相关。预计美国的总体医疗保健成本也可能增加。
