Is Methylergonovine safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Methylergonovine. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
According to the manufacturer, there are isolated reports of adverse effects in breastfed infants whose mothers were receiving methylergonovine for several days. One or more of the following symptoms were observed during methylergonovine therapy and disappeared upon withdrawal of the medication: elevated blood pressure, bradycardia, tachycardia, vomiting, diarrhea, restlessness, or clonic cramps. Another case reported to the manufacturer was a breast-fed infant who presented with seizures after about 4 to 6 days of maternal methylergonovine therapy. The infant s seizures began on the second day of treatment of the mother after breastfeeding. Medications were discontinued per the mother. The infantile seizures resolved about six weeks later.[ 5 ] It is not possible to determine the causality of any of the adverse effects with the information available. A working group of the French national medication safety agency (ANSM) reported 23 cases of infants exposed to methylergonovine via breastmilk who had a total of 44 adverse reactions. (Some of these might be the same as those reported in the preceding paragraph.) The working group considered tachycardia, vomiting, diarrhea and agitation to be sufficiently well documented to add to the prescribing information.[ 6 ] A prospective case-control study compared the outcome of infants whose mothers had taken methylergonovine postpartum 0.125 mg 2 times daily for 5 days or 3 times daily for 3 days to mothers who had taken amoxicillin which served as a control group. Of 29 mothers who had taken methylergonovine, there were no differences in neonatal health or development at follow-up at 17 months postpartum between the treatment and control groups.[ 7 ]
Effects on milk supply
Oral methylergonovine in a dose of 0.2 mg 3 times daily for 7 days in 10 postpartum subjects caused no difference in serum prolactin concentrations from placebo administered to 10 postpartum control women. No significant difference found in the daily milk volumes between the groups.[ 8 ] A single intramuscular injection of methylergonovine 0.2 mg given to 4 women on day 3 postpartum caused a decrease in serum prolactin beginning 45 to 60 minutes after the dose. For 2 to 3 hours after the dose, serum prolactin levels remained about 50% lower than baseline levels.[ 9 ] A single intramuscular injection of methylergonovine 0.2 mg was given to 14 women during the first 1.5 hours postpartum. At 80 to 90 minutes after the injection, the normal postpartum rise in serum prolactin was 56% in the women who received methylergonovine compared to a 285% in serum prolactin in women who received a placebo injection. Six treated women had no increase in serum prolactin compared to 2 of the control women.[ 10 ] Thirty women who delivered fullterm infants received a single intramuscular dose of methylergonovine 0.2 mg after delivery, followed by oral ergotamine 1 mg 3 times daily for 6 days. Compared to 28 women who delivered fullterm infants and received no ergot derivatives, there was no difference in the milk production, as measured by weight differences before and after nursing, between the 2 groups during the first 6 days postpartum.[ 11 ] Thirty postpartum women were given methylergonovine 0.2 mg orally 3 times daily for the first 7 days postpartum. Baseline (prior to nursing) serum prolactin was no different from those of 30 postpartum women who received no methylergonovine on days 1 and 3 postpartum. However, on day 7 postpartum, serum prolactin levels were significantly less in the treated women. Milk production was also reduced in the treated women on days 3 and 7 postpartum compared to controls.[ 12 ] Ten women received a single intravenous dose of 0.4 mg of methylergonovin
Levels in milk
Maternal Levels . After a regimen of oral methylergonovine 0.125 mg 3 times daily for 5 days, a single oral dose of 0.25 mg was given to 8 women. Milk levels 1 hour after the dose ranged from undetectable in 4 women ( 0.5 mcg/L) to 1.3 mcg/L. By 8 hours after the dose, 7 women had undetectable milk levels, although it was 1.2 mcg/L in one individual. The authors estimated that the maximum dosage a breastfed infant would receive after a 7.5 mg daily maternal dosage would be 1.3 mcg which is about 0.3% of the adult dosage.[ 1 ] Methylergonovine maleate 0.75 mg daily was administered to postpartum women for 4 days. The exact dosage regimen and number of women were not reported. Two hours after the last dose, milk samples contained 1.3 mcg/L of methylergonovine.[ 2 ] Ten women who averaged 4.8 days postpartum received a single oral dose of methylergonovine 250 mcg. Milk samples were obtained from one breast from 0.5 to 5 hours after the dose. Average milk levels were 368 ng/L and 527 ng/L at 1 and 2 hours after the dose, respectively. The mean peak milk level was 657 ng/L (range 410-830 ng/L), at 1.8 hours after the dose. In 2 women, the peak milk level occurred 3 hours after the dose. By 5 hours, the average milk level was 200 ng/L. The half-life in breastmilk averaged 2.3 hours.[ 3 ] Twelve mothers were treated with methylergonovine 0.125 mg three times daily for 5 days to treat incomplete postpartum uterine involution. The mothers collected eleven 3 mL samples of milk after an oral dose of 0.125 mg of methylergonovine over the following 12 hours. The average peak milk level was 437 ng/L at 2 hours after the dose. Milk levels fell to an average of 86 ng/L at 5 hours after the dose and were undetectable ( 50 ng/L) at 6 hours and thereafter.[ 4 ] Infant Levels . Relevant published information was not found as of the revision date.
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.