Robinson Dean M, Keating Gillian M
Adis International Limited, Auckland, New Zealand.
Drugs. 2006;66(5):661-8; discussion 669-70. doi: 10.2165/00003495-200666050-00006.
Dexmethylphenidate extended release (XR) is an orally administered, bimodal release, capsule formulation of the active d-enantiomer of methylphenidate (MPH), which inhibits dopamine and norepinephrine (noradrenaline) reuptake to increase their concentration in the extraneuronal space. A single dose of dexmethylphenidate XR mimics the pharmacokinetic profile of two doses of dexmethylphenidate immediate-release formulation administered 4 hours apart, albeit with less fluctuation in plasma concentration. Once-daily dexmethylphenidate XR was more effective than placebo in reducing attention-deficit hyperactivity disorder (ADHD) symptom scores in children, adolescents and adults with ADHD in four randomised, double-blind, placebo-controlled trials of up to 7 weeks' duration. In crossover trials in children (aged 6-12 years), dexmethylphenidate XR 20 mg/day reduced mean ADHD symptom scores 1 hour after administration (by 43% in one trial) and was significantly better than placebo for up to 12 hours. Dexmethylphenidate XR 5-30 mg/day reduced mean ADHD symptom scores by 49%, while scores declined by 16% with placebo in a 7-week trial in children and adolescents (aged 6-17 years). Dexmethylphenidate XR 20, 30 or 40 mg/day reduced ADHD symptom scores by 36-46% versus a 21% reduction with placebo in a 5-week trial in adults (aged 18-60 years). Dexmethylphenidate XR was generally well tolerated in children, adolescents and adults with ADHD, with an adverse-event profile typical of MPH.
右旋哌甲酯缓释剂（XR）是一种口服的、双峰释放的胶囊制剂，其活性成分是哌甲酯（MPH）的右旋对映体，它通过抑制多巴胺和去甲肾上腺素（去甲肾上腺素）的再摄取来增加它们在神经外间隙中的浓度。单剂量的右旋哌甲酯缓释剂模拟了间隔4小时服用两剂右旋哌甲酯速释制剂的药代动力学特征，尽管血浆浓度波动较小。在四项长达7周的随机、双盲、安慰剂对照试验中，每日一次的右旋哌甲酯缓释剂在降低患有注意力缺陷多动障碍（ADHD）的儿童、青少年和成人的ADHD症状评分方面比安慰剂更有效。在儿童（6至12岁）的交叉试验中，右旋哌甲酯缓释剂20毫克/天在给药后1小时降低了平均ADHD症状评分（在一项试验中降低了43%），并且在长达12小时内显著优于安慰剂。在一项针对儿童和青少年（6至17岁）的7周试验中，右旋哌甲酯缓释剂5至30毫克/天使平均ADHD症状评分降低了49%，而安慰剂组评分下降了16%。在一项针对成人（18至60岁）的5周试验中，右旋哌甲酯缓释剂20、30或40毫克/天使ADHD症状评分降低了36%至46%，而安慰剂组降低了21%。右旋哌甲酯缓释剂在患有ADHD的儿童、青少年和成人中通常耐受性良好，具有MPH典型的不良事件谱。
