Methyldopa and Breastfeeding

Summary of use during lactation

Because of the low levels of methyldopa in breastmilk, amounts ingested by the infant are small and would not be expected to cause any adverse effects in breastfed infants. No special precautions are required.

Drug levels in milk and infant serum

Maternal Levels. Three women who were 2 to 15 days postpartum were taking 250 mg of methyldopa orally 3 or 4 times daily. Randomly drawn milk samples had levels of drug and conjugate that ranged from < 0.1 to 0.5 mg/L at a dose of 750 mg daily and were 0.8 mg/L at a dose of 1 gram daily.[1] In 3 women who were 1 to 8 weeks postpartum, peak levels of drug and conjugate occurred between 3 and 6 hours after the dose. Peak levels of drug and conjugate after a dose of 500 mg were 0.2, 0.66 and 1.14 mg/L in 3 mothers' milk. The authors estimated an infant dosage of less than 0.2% of the mother's total dosage.[2] Infant Levels. No methyldopa was detectable (<200 mcg/L) in the serum of an infant whose mother was taking methyldopa 250 mg twice daily. The infant's urine contained a methyldopa concentration of 3.8 mg/L.[3] In an 8-week-old infant whose mother was receiving 1 gram daily of methyldopa, a serum level of 90 mcg/L was found 10 hours after a 500 mg maternal dose. Another 1-week-old infant whose mother was receiving 500 mg daily had no detectable drug in the serum (<50 mcg/L).[2]

Effects in breastfed infants

No acute or long-term adverse effects were reported in any 15 infants ranging in age from less than 1 week to 8 weeks of age whose mothers were taking oral methyldopa 0.25 to 1.5 grams daily.[1-4]

Effects on lactation and breastmilk

Methyldopa can increase serum prolactin and has caused galactorrhea.[5-8] The maternal prolactin level in a mother with established lactation may not affect her ability to breastfeed.

Alternative drugs to consider

Candesartan, Benazepril, Captopril, Enalapril, Lisinopril, Quinapril, Hydrochlorothiazide, Methyldopa, Propranolol

References

1. Jones HM, Cummings AJ. A study of the transfer of alpha-methyldopa to the human foetus and newborn infant. Br J Clin Pharmacol 1978;6:432-4728288 PubMed
2. White WB, Andreoli JW, Cohn RD. Alpha-methyldopa disposition in mothers with hypertension and in their breast-fed infants. Clin Pharmacol Ther 1985;37:387-903838502 PubMed
3. Hauser GJ, Almog S, Tirosh M, et al. Effect of alpha-methyldopa excreted in human milk on the breast-fed infant. Helv Paediatr Acta 1985;40:83-63843238 PubMed
4. Hoskins JA, Holliday SB. Determination of alpha-methyldopa and methyldopate in human breast milk and plasma by ion-exchange chromatography using electrochemical detection. J Chromatogr 1982;230:162-77202013 PubMed
5. Arze RS, Ramos JM, Rashid HU, et al. Amenorrhoea, galactorrhoea, and hyperprolactinaemia induced by methyldopa. Br Med J 1981;283:1946789964 PubMed
6. Turkington RW. Prolactin secretion in patients treated with various drugs: Phenothiazines, tricyclic antidepressants, reserpine, and methyldopa. Arch Intern Med 1972;130:349-544560178 PubMed
7. Vaidya RA, Vaidya AB, Van Woert MH, et al. Galactorrhea and Parkinson-like syndrome: An adverse effect of alpha-methyldopa. Metabolism 1970;19:1068-704923681 PubMed
8. Cohen MA, Davies PH. Drug therapy and hyperprolactinaemia. Adv Drug React Bull 1998:723-6