The Basics
What is Labetalol?
Used to treat high blood pressure.
Brand names for Labetalol
Trandate
How Labetalol is classified
Antihypertensive Agents, Adrenergic Beta-Antagonists, Antiarrhythmics
Labetalol During Pregnancy
Labetalol pregnancy category
Category CNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Labetalol while pregnant
Teratogenic studies were performed with labetalol in rats and rabbits at oral doses up to approximately six and four times the maximum recommended human dose (MRHD), respectively. No reproducible evidence of fetal malformations was observed. Increased fetal resorptions were seen in both species at doses approximating the MRHD. A teratology study performed with labetalol in rabbits at IV doses up to 1.7 times the MRHD revealed no evidence of drug-related harm to the fetus. There are no adequate and well-controlled studies in pregnant women. Labetalol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Taking Labetalol While Breastfeeding
What are recommendations for lactation if you're taking Labetalol?
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.
Maternal / infant drug levels
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.
Possible effects of Labetalol on milk supply
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.[7][8] 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.[9]
Possible alternatives to Labetalol
Propranolol, Metoprolol.
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Riant P, Urien S, Albengres E et al. High plasma protein binding as a parameter in the selection of betablockers for lactating women. Biochem Pharmacol. 1986;35:4579-81. PMID: 2878668
2. Michael CA. Use of labetalol in the treatment of severe hypertension during pregnancy. Br J Clin Pharmacol. 1979;8 (Suppl 2):211S-5S. PMID: 526403
3. Leitz F, Bariletto S, Gural R et al. Secretion of labetalol in breast milk of lactating women. Fed Proc. 1983;42:378. Abstract.
4. Lunell NO, Kulas J, Rane A. Transfer of labetalol into amniotic fluid and breast milk in lactating women. Eur J Clin Pharmacol. 1985;28:597-9. PMID: 4043203
5. Atkinson HC, Begg EJ, Darlow BA. Drugs in human milk. Clinical pharmacokinetic considerations. Clin Pharmacokinet. 1988;14:217-40. PMID: 3292101
6. Mirpuri J, Patel H, Rhee D, Crowley K. What’s mom on? A case of bradycardia in a premature infant on breast milk. J Invest Med. 2008;56:409. Abstract. DOI: doi:10.1097/01.JIM.0000308093.71382.c0
7. Barbieri C, Ferrari C, Caldara R et al. Endocrine and metabolic effects of labetalol in man. J Cardiovasc Pharmacol. 1981;3:986-91. PMID: 6168866
8. Barbieri C, Larovere MT, Mariotti G et al. Prolactin stimulation by intravenous labetalol is mediated inside the central nervous system. Clin Endocrinol (Oxf). 1982;16:615-9. PMID: 7105431
9. McGuinness N, Cording V. Raynaud’s phenomenon of the nipple associated with labetalol use. J Hum Lact. 2013;29:17-9. PMID: 23212937
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
