Division of Maternal-Fetal Medicine, University of Alabama, Birmingham, 619 19th Street South 176F 10270C, Birmingham, AL 35249-7333, USA.
Obstet Gynecol Clin North Am. 2012 Mar;39(1):77-87. doi: 10.1016/j.ogc.2011.12.003. Epub 2012 Jan 4.
The pathophysiology leading to preterm labor is not well understood and often multifactorial; initiating factors include intrauterine infection, inflammation, ischemia, overdistension, and hemorrhage. Given these different potential causes, directing therapy for preterm labor has been difficult and suboptimal. To date, no single drug has been identified as successful in treating all of the underlying mechanisms leading to preterm labor. In addition, the methodology of many of the tocolytic studies is limited by lack of sufficient patient numbers, lack of comparison with a placebo, and inconsistent use of glucocorticoids. The limitations in these individual studies make it difficult to evaluate the efficacy of a single tocolytic by meta-analysis. Despite these limitations, the goals for tocolysis for preterm labor are clear: To complete a course of glucocorticoids and secure the appropriate level of neonatal care for the fetus in the event of preterm delivery. The literature demonstrates that many tocolytic agents inhibit uterine contractility. The decision as to which tocolytic agent should be used as first-line therapy for a patient is based on multiple factors, including gestational age, the patient’s medical history, common and severe side effects, and a patient’s response to therapy. In a patient at less than 32 weeks gestation, indomethacin may be a reasonable first choice based on its efficacy, ease of administration, and minimal side effects. Concurrent administration of magnesium for neuroprotection may be given. At 32 to 34 weeks, nifedipine may be a reasonable first choice because it does not carry the fetal risks of indomethacin at these later gestational ages, is easy to administer, and has limited side effects relative to beta-mimetics. In an effort to review a commonly faced obstetrical complication, this article has provided a summary of the most commonly used tocolytics, their mechanisms of action, side effects, and clinical data regarding their efficacy.
导致早产的病理生理学机制尚不清楚，且往往是多因素的；起始因素包括宫内感染、炎症、缺血、过度扩张和出血。鉴于这些不同的潜在原因，早产的治疗一直很困难，效果也不理想。迄今为止，还没有一种药物被确定能成功治疗导致早产的所有潜在机制。此外，许多保胎药物研究的方法学受到缺乏足够的患者数量、缺乏与安慰剂的比较以及糖皮质激素使用不一致的限制。这些单独研究的局限性使得通过荟萃分析评估单一保胎药物的疗效变得困难。尽管存在这些局限性，但早产保胎的目标是明确的：完成糖皮质激素疗程，并为早产儿提供适当水平的新生儿护理。文献表明，许多保胎药物抑制子宫收缩。选择哪种保胎药物作为患者的一线治疗药物取决于多个因素，包括胎龄、患者的病史、常见和严重的副作用以及患者对治疗的反应。对于妊娠不足 32 周的患者，基于其疗效、给药方便性和最小的副作用，吲哚美辛可能是合理的首选药物。可能会同时给予镁以进行神经保护。在 32 至 34 周时，硝苯地平可能是合理的首选药物，因为它在这些较晚的胎龄阶段不会带来与吲哚美辛相同的胎儿风险，给药方便，且与β激动剂相比副作用有限。为了回顾常见的产科并发症，本文总结了最常用的保胎药物及其作用机制、副作用以及关于其疗效的临床数据。
