Thiagarajah S, Harbert G M, Bourgeois F J
Am J Obstet Gynecol. 1985 Nov 15;153(6):666-74. doi: 10.1016/s0002-9378(85)80256-8.
Effects of magnesium sulfate and ritodrine hydrochloride on cardiovascular physiologic characteristics were studied in 70 human subjects treated for preterm labor. Systemic and uterine hemodynamic effects were investigated in five pregnant rhesus monkeys. Systolic blood pressure was minimally affected by either agent. Diastolic pressure, while not affected by magnesium sulfate, decreased 26.3% during ritodrine therapy. Maternal and fetal heart rates were minimally affected by magnesium sulfate. Ritodrine increased maternal and fetal heart rates significantly. In the monkeys, magnesium sulfate increased uterine and placental blood flows (by the microsphere technique) but failed to alter cardiac output. Ritodrine produced an increase in cardiac output but decreased perfusion pressure. Placental blood flow decreased by an average of 27.6%. Ritodrine would therefore seem contraindicated with a compromised fetal environment. Magnesium sulfate, by not altering perfusion pressure, may have a beneficial effect on uterine hemodynamics. These specific and distinct differences in cardiovascular and hemodynamic effects should be considered when either magnesium sulfate or ritodrine is selected as a tocolytic agent.
在70例接受早产治疗的人体受试者中研究了硫酸镁和盐酸利托君对心血管生理特征的影响。在5只怀孕的恒河猴中研究了全身和子宫血流动力学效应。两种药物对收缩压的影响均最小。舒张压虽不受硫酸镁影响，但在利托君治疗期间下降了26.3%。硫酸镁对母体和胎儿心率的影响最小。利托君显著增加母体和胎儿心率。在猴子中，硫酸镁增加了子宫和胎盘血流量（通过微球技术），但未能改变心输出量。利托君使心输出量增加，但降低了灌注压。胎盘血流量平均减少了27.6%。因此，在胎儿环境受损的情况下，利托君似乎是禁忌的。硫酸镁不改变灌注压，可能对子宫血流动力学有有益作用。在选择硫酸镁或利托君作为宫缩抑制剂时，应考虑这些在心血管和血流动力学效应方面的具体和明显差异。
