毒理性
◉ 母乳喂养期间使用概述：由于乳母乳中的拉贝洛尔含量较低，婴儿摄入的量很小，在足月母乳喂养的婴儿中不会预期引起任何不良反应。在大多数婴儿中不需要特别的预防措施。然而，在喂养早产儿时，可能需要优先考虑其他药物。拉贝洛尔可能会使哺乳母亲乳头雷诺现象的倾向增加。
◉ 对母乳喂养婴儿的影响：一位研究者报告，母亲每天服用330至800毫克拉贝洛尔的剂量时，母乳喂养的婴儿没有出现不良反应。
一个26周早产儿，体重640克，在生命第8天开始通过鼻胃管喂养母亲的泵奶后，出现了窦性心动过缓（80至90次/分钟）和孤立性房性早搏。母亲每天两次口服拉贝洛尔300毫克治疗高血压。在用配方奶替代母乳后24小时内，心动过缓和早搏消失。没有发现其他导致心动过缓的原因。母亲的一份未定时母乳样本中含有710微克/升的拉贝洛尔。尽管作者估计婴儿的剂量为每天100毫克/千克，但使用他们的数据重新计算表明，婴儿的剂量仅为每天100微克/千克。
一个2个月大的婴儿正在被一位每天两次服用拉贝洛尔100毫克的母亲纯母乳喂养。婴儿的心电图心率规律，但QT间期边界性延长。婴儿开始每天服用1毫克/千克的普萘洛尔治疗婴儿血管瘤。一个月后，婴儿的QT间期恢复正常。第二个婴儿被一位每天两次服用拉贝洛尔150毫克和硝苯地平60毫克的母亲纯母乳喂养。婴儿开始每天服用0.6毫克/千克的普萘洛尔治疗婴儿血管瘤。两周内普萘洛尔的剂量增加到每天3.4毫克/千克。在较高剂量的普萘洛尔下，婴儿有一些睡眠困难，但没有其他症状。
◉ 对泌乳和母乳的影响：静脉注射拉贝洛尔可以增加男性的血清催乳素，尽管在女性中增加的幅度更大。口服拉贝洛尔不会增加血清催乳素。在已建立泌乳的母亲中，母体催乳素水平可能不会影响她的哺乳能力。
一位有雷诺现象症状史的女性在用拉贝洛尔100毫克每天两次治疗妊娠高血压时，出现了乳头雷诺现象。她哺乳了5周，但哺乳导致她的乳头疼痛。在随后的怀孕中，在用拉贝洛尔100毫克每天两次治疗期间，出现了类似的症状。停用拉贝洛尔在两种情况下都消除了乳头疼痛。
一位孕妇两次因先兆子痫接受静脉注射拉贝洛尔治疗。每次她都报告了乳头烧灼感。在继续使用拉贝洛尔的同时，她的治疗方案中加入了缓释硝苯地平，乳头烧灼感没有再出现。
◉ Summary of Use during Lactation:Because of the low levels of labetalol in breastmilk, amounts ingested by the infant are small and would not be expected to cause any adverse effects in fullterm breastfed infants. No special precautions are required in most infants. However, other agents may be preferred while nursing a preterm infant. Labetalol may predispose nursing mothers to Raynaud’s phenomenon of the nipple.
◉ Effects in Breastfed Infants:One investigator reported that no adverse effects occurred in breastfed infants whose mothers were taking labetalol in doses of 330 to 800 mg daily.
A 26-week premature infant weighing 640 grams developed sinus bradycardia (80 to 90 bpm) and isolated atrial premature beats after nasogastric feeding with mother's pumped breastmilk was begun on day 8 of life. The mother was taking labetalol 300 mg twice daily by mouth for hypertension. Bradycardia and premature beats resolved within 24 hours of substitution of formula for breastmilk. No other causes for the bradycardia could be identified. One untimed sample of the mother's breastmilk contained 710 mcg/L of labetalol. Although the authors estimated the infant's dose to be 100 mg/kg daily, a recalculation using their data indicates that the infant's dose was only 100 mcg/kg daily.
A 2-month-old infant was being breastfed exclusively by a mother taking labetalol 100 mg twice daily. The infants electrocardiogram had a regular heart rate, but borderline prolonged QT. The infant was started on propranolol 1 mg/kg daily for infantile hemangioma. One month later, the infant had a normal QT interval. A second infant was exclusively breastfed by a mother taking labetalol 150 mg twice daily and nifedipine 60 mg daily. The infant was started on propranolol 0.6 mg/kg daily for infantile hemangioma. The propranolol dose was increased over 2 weeks to 3.4 mg/kg daily. The infant had some sleeping difficulties with the higher propranolol dose, but no other symptoms.
◉ Effects on Lactation and Breastmilk:Intravenous labetalol can increase serum prolactin in men and non-nursing women, although the increase is greater in women. Oral labetalol does not increase serum prolactin. The maternal prolactin level in a mother with established lactation may not affect her ability to breastfeed.
A woman with a history of symptoms of Raynaud's phenomenon developed Raynaud's phenomenon of the nipples when treated for pregnancy-induced hypertension with labetalol 100 mg twice daily. She breastfed for 5 weeks, but nursing caused pain in her nipples. In a subsequent pregnancy, similar symptoms occurred during treatment with labetalol 100 mg twice daily. Discontinuing labetalol eliminated the nipple pain in both instances.
A pregnant woman was treated on two occasions with intravenous labetalol for pre-eclampsia. On each occasion, she reported a burning sensation of the nipples. While continuing on labetalol, sustained-release nifedipine was added to her regimen and the burning of the nipple did not return.
来源:Drugs and Lactation Database (LactMed)
