Macher Jean-Paul, Lévy Samuel
Rouffach, France.
Clin Drug Investig. 2009;29(5):339-48. doi: 10.2165/00044011-200929050-00006.
Ivabradine is a novel pure heart rate-lowering agent that selectively and specifically inhibits pacemaker I(f) current. Ivabradine has been shown to have antianginal and anti-ischaemic properties in patients with stable angina pectoris. Because f channels are also present in the retina, visual symptoms represent a potential adverse effect of ivabradine that may affect driving performance. The aim of the study was to investigate whether visual symptoms reported after repeated administration of ivabradine at high doses could affect driving performance.
This randomized, double-blind, placebo-controlled study was conducted in healthy volunteers. Seventy-five subjects were randomized to ivabradine 10 mg twice daily and 15 subjects to placebo for 7 days, followed by ivabradine 15 mg twice daily or placebo, respectively, for a second week if no visual symptoms were reported. As soon as a subject reported visual symptoms between day 1 and day 14, he or she was assigned to perform driving simulator sessions. If no visual symptoms were reported, driving simulator sessions were performed after 14 days' treatment. Driving parameters included absolute speed, deviation from the speed limit, deviation from the ideal route and number of collisions in different light conditions.
In the daylight and evening driving sessions, there was no significant difference in all measured parameters (as indicated by absolute speed, deviation from the speed limit and deviation from the ideal route results) between the ivabradine and the placebo groups, independently of visual symptoms. No collisions were observed in the entire study irrespective of the testing conditions and the treatment groups assessed. No relevant differences were seen in the ivabradine subsets of subjects reporting visual symptoms or not.
This study suggests that ivabradine administered at dosages higher than those recommended in the clinic did not affect driving performance regardless of whether or not visual symptoms were present.
伊伐布雷定是一种新型的单纯降低心率药物,可选择性、特异性地抑制起搏电流I(f)。在稳定性心绞痛患者中,伊伐布雷定已被证明具有抗心绞痛和抗缺血特性。由于视网膜中也存在f通道,视觉症状是伊伐布雷定可能影响驾驶能力的潜在不良反应。本研究旨在调查重复高剂量服用伊伐布雷定后报告的视觉症状是否会影响驾驶能力。
本随机、双盲、安慰剂对照研究在健康志愿者中进行。75名受试者被随机分为每日两次服用10mg伊伐布雷定组,15名受试者服用安慰剂,为期7天;如果未报告视觉症状,第二周分别改为每日两次服用15mg伊伐布雷定或安慰剂。一旦受试者在第1天至第14天之间报告视觉症状,即安排其进行驾驶模拟器测试。如果未报告视觉症状,则在治疗14天后进行驾驶模拟器测试。驾驶参数包括绝对速度、与限速的偏差、与理想路线的偏差以及在不同光照条件下的碰撞次数。
在白天和夜间驾驶测试中,伊伐布雷定组和安慰剂组之间所有测量参数(如绝对速度、与限速的偏差和与理想路线的偏差结果所示)均无显著差异,与视觉症状无关。在整个研究中,无论测试条件和评估的治疗组如何,均未观察到碰撞情况。在报告视觉症状和未报告视觉症状的伊伐布雷定受试者亚组中,未见相关差异。
本研究表明,以高于临床推荐剂量给药的伊伐布雷定,无论是否出现视觉症状,均不影响驾驶能力。