Functional neuroimaging of cognition impaired by a classical antihistamine, d-chlorpheniramine
Functional neuroimaging of cognition impaired by a classical antihistamine, d-chlorpheniramine
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DOI：
10.1038/sj.bjp.0702994
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发表时间：
2000-01-01
影响因子：
7.3
通讯作者：
Itoh, M
中科院分区：
文献类型：
--
作者：
Okamura, N;Yanai, K;Itoh, M
1采用正电子发射断层扫描（PET）测量组胺H1受体（HIR）占用和局部脑血流量（rCBF）来评估抗组胺诱导的认知能力下降注意要求任务的认知表现呈剂量依赖性恶化，2 mg d-氯苯那敏治疗后效果有统计学意义。在相同剂量下，主观困倦感没有显著变化H1R的区域阻断主要在额叶、颞叶和前扣带皮层，静脉注射d-氯苯那敏作为治疗剂量（2毫克）阻断额叶皮层60%以上的H1R使用视觉辨别任务进行的激活研究结果表明，d-氯苯那明治疗后，右侧前额叶和前扣带皮层的活动增强，左侧颞叶和额叶皮层以及中脑的活动减弱接受2mg d-氯苯那敏治疗的受试者总体CBF没有变化(治疗前；44.8+/-3.3 ml dl(-1) min(-1) vs治疗后；44.4±4.7 ml dl(-1) min（-1）结果表明，HIR拮抗剂的治疗剂量可以改变人脑的注意系统。这些发现为我们日常活动中抗组胺药的潜在风险提供了信息。
1 Antihistamine induced cognitive decline was evaluated using positron emission tomography (PET) measurement of histamine H1 receptor (HIR) occupancy and regional cerebral blood flow (rCBF).2 Cognitive performance in attention-demanding task deteriorated dose-dependently and the effects were statistically significant after the treatment of 2 mg of d-chlorpheniramine. There was no significant change in subjective sleepiness in the same dose.3 The regional blockade of H1R was observed mainly in the frontal, temporal and anterior cingulate cortices, and the intravenous administration of d-chlorpheniramine as a therapeutic dose (2 mg) blocked over 60% of H1R in the frontal cortices.4 The results from activation study using visual discrimination tasks demonstrated that enhanced activity in the right prefrontal and anterior cingulate cortices as well as a decreased activity in the left temporal and frontal cortices and midbrain after the treatment of d-chlorpheniramine.5 There were no changes in global CBF for the subjects treated with 2 mg d-chlorpheniramine (pre; 44.8+/-3.3 ml dl(-1) min(-1) vs post; 44.4+/-4.7 ml dl(-1) min(-1)).6 The results indicated that the attention system of human brain could be altered by therapeutic doses of HIR antagonists. These findings provide the information as to the potential risk of antihistamines in our daily activities.