Rungsanpanya Thipparut, Muangpaisan Weerasak, Praditsuwan Roongnirand
Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
J Med Assoc Thai. 2012 Aug;95(8):1081-9.
Cholinesterase inhibitors and N-methyl-D-aspartate antagonist have been used increasingly for patients with dementia. However these products are relatively costly and have been linked to many adverse events. Only a few surveys of prescribing patterns of drugs for dementia have been conducted in developing countries, while the proportion of dementia patients is expected to become higher in these regions. We aim to evaluate the utilization patterns, adverse events, and cost of antidementia drugs in a geriatric clinic at Siriraj hospital.
Data was obtained from the medical records of dementia patients who were newly diagnosed between January 2007 and December 2009 in the Geriatric clinic, Siriraj hospital, Bangkok. The diagnosis was based on DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-IV) criteria.
Ninety-six elderly patients were diagnosed with dementia during the studied period. Eighty patients (83.30%) with the average age of 80.6 (SD = 7) years received antidementia drugs. Donepezil was the most frequently prescribed drug (70%), followed by rivastigmine (22.5%). Concomitant use of interacting drugs was noted in 41.3% of patients. The average prescribed daily dose of rivastigmine, galantamine and memantine were lower than their effective defined daily dose. The highest average cost per year was galantamine (60,020.5 baht/year) and the lowest one was memantine (45,857.7 baht/year). Among cholinesterase inhibitors receivers, 43.5% had at least one adverse event. Thirty-seven percent of these were gastrointestinal side effects. Only 12.5% of memantine-receivers developed adverse events. One-year drug discontinuation rates were 26.1% and 12.5% in cholinesterase inhibitor and memantine groups, respectively. From multivariate logistic regression analysis, the only factor associated with adverse drug events was the presence of behavioral and psychological symptoms.
The majority of dementia patients in our study were prescribed antidementia drugs. Half of them developed adverse events, but one-year drug discontinuation was relatively low. The average daily doses were lower than recommended doses. Future prospective studies should be performed to determine the cost-effectiveness and establish evidence-based practice guideline for management of dementia patients.
胆碱酯酶抑制剂和N-甲基-D-天冬氨酸拮抗剂已越来越多地用于痴呆患者。然而，这些产品相对昂贵，且与许多不良事件有关。在发展中国家，仅开展了少数几项关于痴呆症药物处方模式的调查，而预计这些地区痴呆症患者的比例将更高。我们旨在评估诗里拉吉医院老年诊所抗痴呆药物的使用模式、不良事件和成本。
数据来自2007年1月至2009年12月在曼谷诗里拉吉医院老年诊所新诊断的痴呆患者的病历。诊断基于DSM-IV（《精神疾病诊断与统计手册》第四版）标准。
在研究期间，96名老年患者被诊断为痴呆。80名患者（83.30%）平均年龄为80.6岁（标准差=7），接受了抗痴呆药物治疗。多奈哌齐是最常处方的药物（70%），其次是卡巴拉汀（22.5%）。41.3%的患者存在相互作用药物的联合使用情况。卡巴拉汀、加兰他敏和美金刚的平均每日处方剂量低于其有效限定日剂量。每年平均成本最高的是加兰他敏（60,020.5泰铢/年），最低的是美金刚（45,857.7泰铢/年）。在胆碱酯酶抑制剂使用者中，43.5%至少发生过一次不良事件。其中37%为胃肠道副作用。仅12.5%的美金刚使用者出现不良事件。胆碱酯酶抑制剂组和美金刚组的一年停药率分别为26.1%和12.5%。多因素逻辑回归分析显示，与药物不良事件相关的唯一因素是存在行为和心理症状。
我们研究中的大多数痴呆患者都接受了抗痴呆药物治疗。其中一半出现了不良事件，但一年停药率相对较低。平均每日剂量低于推荐剂量。未来应开展前瞻性研究，以确定成本效益，并为痴呆患者的管理制定循证实践指南。
