Methylergonovine
CASRN: 113-42-8
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Drug Levels and Effects:
Summary of Use during Lactation:
Limited information indicates that maternal doses of methylergonovine up to 0.75 mg daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants. Although results of several imperfect studies are somewhat mixed, it appears that methylergonovine can decrease serum prolactin and possibly the amount of milk production and duration of lactation, especially when used in the immediate postpartum period. The effect seems to be related to the dosage and route of administration, with injected doses having a greater impact than oral. A few oral doses may not severely affect lactation; however, methylergonovine is probably best avoided in mothers who wish to nurse, relying instead on suckling-induced oxytocin release to hasten uterine involution. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.
Drug Levels:
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]
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. 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 mean milk level was 0.2 ng/L. The half-life in milk averaged 2.3 hours.[2]
Infant Levels. Relevant published information was not found as of the revision date.
Effects in Breastfed Infants:
Relevant published information was not found as of the revision date.
Possible Effects on Lactation:
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.[3]
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.[4]
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.[5]
Thirty women who delivered full-term 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 full-term 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.[6]
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.[7]
Ten women received a single intravenous dose of 0.4 mg of methylergonovine immediately postpartum were compared to 10 control mothers who received no methylergonovine; all women received a continuous infusion of oxytocin postpartum. None of the women were allowed to nurse or extract milk from their breasts or to receive hormones to suppress lactation. Serum prolactin measured during labor, immediately after administration of the drug and daily at 9 am for 5 days postpartum found no statistical differences in prolactin levels between the 2 groups.[8]
In a randomized study, 48 patients were given methylergonovine 0.125 mg orally every 8 hours for the first 7 days postpartum. Another 44 in the same hospital were not given methylergonovine. No statistical differences were found in the serum levels of prolactin at 3 days postpartum between the groups, although women with normal deliveries had higher prolactin levels than those delivered by cesarean section. At 1 month postpartum, no differences were found in the percentage of exclusive breastfeeding or in the weight gain of infants.[9]
In a prospective, randomized study, 444 postpartum mothers were given 0.125 mg of methylergonovine 3 times a day, while 436 were given placebo. Milk production among untreated women averaged 880 grams during the first 6 days, while among treated patients it was only 563 grams. After 4 weeks there were still differences in the quantity of milk produced.[10]
References:
1. Erkkola R, Kanto J et al. Excretion of methylergometrine (methylergonovine) into the human breast milk. Int J Clin Pharmacol Biopharm. 1978;16:579-80. PMID: 730424
2. Vogel D, Burkhardt T, Rentsch K et al. Misoprostol versus methylergometrine: pharmacokinetics in human milk. Am J Obstet Gynecol. 2004;191:2168-73. PMID: 15592308
3. del Pozo E, Brun del Rey RB, Hinselmann M. Lack of effect of methyl-ergonovine on postpartum lactation. Am J Obstet Gynecol. 1975;123:845-6. PMID: 1200082
4. Perez-Lopez FR, Delvoye P, Denayer P et al. Effect of methylergobasine maleate on serum gonadotrophin and prolactin in humans. Acta Endocrinol (Copenh). 1975;79:644-57. PMID: 1174274
5. Weiss G, Klein S et al. Effect of methylergonovine on puerperal prolactin secretion. Obstet Gynecol. 1975;46:209-10. PMID: 1080266
6. Jolivet A, Robyn C et al. [Effect of ergot alkaloid derivatives on milk secretion in the immediate postpartum period]. J Gynecol Obstet Biol Reprod (Paris). 1978;7:129-34. PMID: 641312
7. Peters F, Lummerich M, Breckwoldt M. Inhibition of prolactin and lactation by methylergometrine hydrogenmaleate. Acta Endocrinol (Copenh). 1979;91:213-6. PMID: 463447
8. del Castillo FJ, Ramirez BM, Diaz-Infante Ibarra A. [Effect of methylergovine on the secretion of prolactin in childbirth and the puerperium]. Ginecol Obstet Mex. 1980;48:311-6. PMID: 7250712
9. Gonzalez P, Gayan P et al. [Plasma prolactin in the puerperium and its relation to the use of methylergonovine maleate.] Rev Chil Obstet Ginecol. 1984;49:149-55. PMID: 6543471
10. Arabin B, Ruttgers H, Kubli F. [Effects of routine administration of methylergometrine during puerperium on involution, maternal morbidity and lactation]. Geburtshilfe Frauenheilkd. 1986;46:215-20. PMID: 3519353
Substance Identification:
Substance Name: Methylergonovine
CAS Registry Number: 113-42-8
Drug Class:
Ergot Alkaloids
Oxytocics
Administrative Information:
LactMed Record Number:
467
Last Revision Date:
20101207
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