Landahl S, Andersson T, Larsson M, Lernfeldt B, Lundborg P, Regårdh C G, Sixt E, Skånberg I
Department of Geriatric and Longterm Care Medicine, Clinic IV, Vasa Hospital, Göteborg, Sweden.
Clin Pharmacokinet. 1992 Dec;23(6):469-76. doi: 10.2165/00003088-199223060-00006.
The pharmacokinetics of omeprazole and its metabolites were studied in 8 healthy elderly volunteers using [14C]omeprazole. In another 6 healthy elderly volunteers, the pharmacokinetics of omeprazole were studied using unlabelled drug. Each volunteer received single doses of omeprazole intravenously (20mg) and orally (40mg) as solutions in a randomized crossover design. The plasma concentrations and urinary excretion of omeprazole and metabolites were followed for 24 and 96h, respectively. The results indicate that the average metabolic capacity of omeprazole is decreased in the elderly compared with that found in earlier studies of healthy young individuals. This was reflected in an increase in bioavailability from 56 to 76%, a reduction in mean systemic clearance by approximately 50% (0.25 L/min) and a prolongation of the mean elimination half-life from 0.7 to 1.0h compared with the young. Despite these findings, the considerable overlap in these parameters between young and old volunteers, together with data from previous pharmacodynamic studies and the wide therapeutic range of omeprazole, indicate that dosage reductions are not needed in the elderly.
使用[14C]奥美拉唑对8名健康老年志愿者进行了奥美拉唑及其代谢产物的药代动力学研究。在另外6名健康老年志愿者中，使用未标记药物研究了奥美拉唑的药代动力学。每位志愿者均按照随机交叉设计，静脉注射（20mg）和口服（40mg）单剂量的奥美拉唑溶液。分别在24小时和96小时内跟踪奥美拉唑及其代谢产物的血浆浓度和尿排泄情况。结果表明，与早期对健康年轻个体的研究相比，老年人中奥美拉唑的平均代谢能力有所下降。这表现为生物利用度从56%增加到76%，平均全身清除率降低约50%（0.25L/分钟），平均消除半衰期从0.7小时延长至1.0小时。尽管有这些发现，但年轻和老年志愿者在这些参数上有相当大的重叠，再加上先前药效学研究的数据以及奥美拉唑广泛的治疗范围，表明老年人无需减少剂量。
