Pacifici Gian Maria
Department of Neurosciences, Section of Pharmacology, Medical School, Via Roma 55, 56126 Pisa, Italy.
Early Hum Dev. 2005 Aug;81(8):647-54. doi: 10.1016/j.earlhumdev.2005.02.002.
Viruses cross the placenta and infect the fetus. Antivirals are administered to pregnant women to protect them and the fetus against the viruses. It is necessary to know which antivirals cross the placenta and reach the fetal circulation in pharmacologically significant concentrations in order to plan antiviral therapy.
This article reviews the literature on the placental transfer of antivirals against HIV. The review considers also the placental transfer of acyclovir and ganciclovir, which are used against the herpes simplex virus and the cytomegalovirus, respectively.
Firstly, a medline was performed with the following key words "placental transfer of antivirals". Secondly, a medline was performed with the key words "placenta transfer of..." followed by the name of a single antiviral and it was repeated for 20 antivirals. Thirdly, another medline was performed using the following key words "pharmacokinetics of antiviral in newborn" in order to collect those articles which describe in vivo transfer of antivirals. The literature was critically read and a written note was produced.
The literature on the placental transfer of antivirals includes studies in vitro perfusing the human placenta and studies performed in vivo in which the cord and maternal antiviral plasma concentrations are compared. Both the results obtained in vitro and in vivo show that the protease inhibitors poorly transfer the placenta because of their great molecular weight. With the exception of didanosine, the nucleoside reverse transcriptase inhibitors and nelfinavir, a non-nucleoside reverse transcriptase inhibitor, cross the placenta and the cord, and maternal plasma concentrations equilibrate.
In vitro and in vivo results are consistent with the view that the nucleoside reverse transcriptase inhibitors cross the human placenta and produce significant pharmacological concentrations in the fetal circulation. Nevirapine, the only studied non-nucleoside reverse transcriptase inhibitor, reach the equilibrium between the fetal and maternal concentration, whereas the protease inhibitors have a poor transfer across the human placenta.
病毒可穿过胎盘并感染胎儿。给孕妇使用抗病毒药物以保护她们及胎儿免受病毒侵害。为了规划抗病毒治疗，有必要了解哪些抗病毒药物能穿过胎盘并以具有药理学意义的浓度进入胎儿循环。
本文综述了关于抗HIV抗病毒药物胎盘转运的文献。该综述还考虑了分别用于治疗单纯疱疹病毒和巨细胞病毒的阿昔洛韦和更昔洛韦的胎盘转运情况。
首先，使用关键词“抗病毒药物的胎盘转运”进行医学文献检索。其次，使用关键词“……的胎盘转运”并紧跟一种单一抗病毒药物的名称进行医学文献检索，对20种抗病毒药物重复此操作。第三，使用关键词“新生儿抗病毒药物的药代动力学”进行另一轮医学文献检索，以收集那些描述抗病毒药物体内转运的文章。对文献进行严格阅读并撰写笔记。
关于抗病毒药物胎盘转运的文献包括体外灌注人胎盘的研究以及体内比较脐带血和母体抗病毒血浆浓度的研究。体外和体内获得的结果均表明，蛋白酶抑制剂因分子量较大而难以穿过胎盘。除去羟肌苷外，核苷类逆转录酶抑制剂和非核苷类逆转录酶抑制剂奈非那韦可穿过胎盘和脐带，母体血浆浓度达到平衡。
体外和体内结果均支持核苷类逆转录酶抑制剂可穿过人胎盘并在胎儿循环中产生显著药理学浓度这一观点。奈韦拉平是唯一被研究的非核苷类逆转录酶抑制剂，其在胎儿和母体浓度之间达到平衡，而蛋白酶抑制剂穿过人胎盘的能力较差。
