Howe J P, McGowan W A, Moore J, McCaughey W, Dundee J W
Anaesthesia. 1981 Apr;36(4):371-5. doi: 10.1111/j.1365-2044.1981.tb10240.x.
The placental transfer of cimetidine 200 mg intravenously was investigated in 16 patients in normal labour and 40 patients undergoing elective Caesarean section. Cimetidine crosses the placental barrier, blood levels at delivery in mothers and infants being lower with increasing time from injection. Umbilical cord blood cimetidine levels are markedly lower than those of the mother during the first hour following administration but thereafter levels are similar. The mean fetal-maternal ratio at delivery was highest (0.84) at 1 1/2-2 hours following administration. Postdelivery infant and maternal blood samples showed that cimetidine could not be detected, in most cases, 19 hours following administration. The relevance of these findings is discussed.
对16名正常分娩的患者和40名接受择期剖宫产的患者静脉注射200毫克西咪替丁后的胎盘转运情况进行了研究。西咪替丁可穿过胎盘屏障，随着注射后时间的增加，母亲和婴儿分娩时的血药浓度降低。给药后第一小时内，脐血中西咪替丁水平明显低于母亲，但此后水平相似。给药后1.5至2小时，分娩时胎儿与母亲的平均比值最高（0.84）。产后婴儿和母亲的血样显示，在大多数情况下，给药19小时后检测不到西咪替丁。讨论了这些发现的相关性。
