Yonekura Y, Nishizawa S, Tanaka F, Ishizu K, Okazawa H, Fujita T, Konishi J, Torizuka K
Department of Brain Pathophysiology, School of Medicine, Kyoto University.
Kaku Igaku. 1995 Jan;32(1):87-97.
A Phase 1 clinical study of 123I-iomazenil (IMZ), a new radiopharmaceutical developed for evaluation of central-type benzodiazepine receptor (BZR) with SPECT, was performed to examine its safety and biodistribution in six healthy volunteers. The brain uptake of 123I-IMZ reached a maximum value of 11.7 +/- 1.6% of the injected dose at 10-20 min after i.v. administration, and then decreased slowly. The regional tracer distribution immediately after injection (0-10 min) was considered to be a reflection of the cerebral blood flow. From 2 to 3 hours post-injection, washout of the radioactivity from the deep gray matter was observed, resulting in the distribution reflecting the reported distribution of BZR. No significant accumulation was seen in any organ other than the brain. The estimated absorbed dose of 123I-IMZ calculated by the MIRD method was comparable to that of 123I-N-isopropyl-p-iodoamphetamine. Neither adverse reactions nor abnormal clinical laboratory findings due to the drug administration were observed. These results suggest that 123I-IMZ is a safe and promising agent for evaluating the function of central-type BZR.
一项针对123I-碘美西尼（IMZ）的1期临床研究在6名健康志愿者中开展，123I-碘美西尼是一种新开发的放射性药物，用于通过单光子发射计算机断层扫描（SPECT）评估中枢型苯二氮䓬受体（BZR）。研究旨在考察其安全性和生物分布情况。静脉注射后，123I-碘美西尼在脑内的摄取在10至20分钟时达到最大值，为注射剂量的11.7±1.6%，随后缓慢下降。注射后即刻（0至10分钟）的局部示踪剂分布被认为反映了脑血流量。注射后2至3小时，观察到放射性从深部灰质中洗脱，从而使其分布反映出已报道的BZR分布情况。除脑以外，未在任何器官中观察到明显的放射性蓄积。通过医学内照射剂量（MIRD）方法计算的123I-碘美西尼的估计吸收剂量与123I-N-异丙基-p-碘安非他明的相当。未观察到因给药导致的不良反应或异常临床实验室检查结果。这些结果表明，123I-碘美西尼是一种用于评估中枢型BZR功能的安全且有前景的药物。
