Is Promethazine safe while breastfeeding?
Here is what LactMed, the Drugs and Lactation Database published by the U.S. National Institute of Child Health and Human Development (NICHD), reports about Promethazine. The text below is quoted from that source — it is not our own verdict.
Summary of use during breastfeeding
Based on minimal excretion of other phenothiazine derivatives, it appears that occasional short-term use of promethazine for the treatment of nausea and vomiting poses little risk to the breastfed infant. With repeated doses, observe infants for excess sedation. Because promethazine can lower basal prolactin secretion, promethazine might interfere with the establishment of lactation if given during labor before lactation is well established or with a sympathomimetic such as pseudoephedrine. An antiemetic without potent histamine blocking action is preferred in nursing mothers.
Effects on the breastfed infant
Relevant published information was not found as of the revision date.
Effects on milk supply
Unlike most phenothiazines, promethazine usually causes a reduction in basal prolactin secretion in nonnursing women.[1,2] In one small study, women given promethazine with meperidine and secobarbital during labor, had the time to lactogenesis II prolonged by 14 hours. Women given meperidine or secobarbital without promethazine had lactogenesis II prolonged 7 hours compared to unmedicated women, but the difference was not statistically significant.[3] The effect of postpartum promethazine is not known, but it might interfere with the establishment of lactation if given in the early postpartum period.
Levels in milk
Maternal Levels. Relevant published information was not found as of the revision date.
Infant Levels. Relevant published information was not found as of the revision date.
Alternatives LactMed lists
Promethazine in pregnancy
LactMed covers breastfeeding only. For what the NHS and the US prescribing label say about pregnancy, see:
Source: Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Promethazine” (LM228). LactMed on NCBI Bookshelf. LactMed is a registered trademark of the U.S. Department of Health and Human Services.
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.