Drug Levels and Effects:

Summary of Use during Lactation:

Limited milk level and infant data and a long history of use in postpartum mothers indicate that hydralazine is an acceptable antihypertensive in nursing mothers, even those nursing newborns.

Drug Levels:

Maternal Levels

In one case report, a mother taking oral hydralazine 50 mg 3 times daily for at least 8 weeks postpartum had hydralazine milk levels of about 130 mcg/L at 0.5 and 2 hours after a dose. In addition, milk contained an amount of acid-labile hydrazones with undefined pharmacologic activity. The authors estimated that a breastfed infant would receive a maximum of 13 mcg per feeding at this maternal dosage.[1]

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

No adverse effects reported in one infant breastfed for 8 weeks.[1]

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.

Alternate Drugs to Consider:



1. Liedholm H, Wahlin-Boll E, Hanson A et al. Transplacental passage and breast milk concentration of hydralazine. Eur J Clin Pharmacol. 1982;21:417-9. PMID:7200428

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Antihypertensive Agents

  • Vasodilator Agents

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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