Is Metronidazole compatible with breastfeeding? Do we have alternatives for Metronidazole?


August 29, 2018 (Very Low Risk)

Antiinfective of the family of imidazoles indicated in the treatment of giardiasis, amebiasis, trichomoniasis and anaerobic infections (bacteroides and clostridium).
Oral administration one to three times a day. Intravenous use in severe cases.
Authorized and widely used in Pediatrics. The dose in minors of two months is 15 mg / kg / day and in greater than two months of 30 mg / kg / day (AEMPS 2018).
There are ancient studies that proved carcinogenic effects in rats receiving high doses. This has not been demonstrated in humans (Falagas 1998, Fahrig 1997, Beard 1988, Roe 1985), there is still much controversy (Adil 2018, Friedman 2009) and metronidazole is one of the most used antibiotics in vaginal, intestinal and other infections and whose use in humans is spreading (Adil 2018, Sobel 2015).

It is excreted in breast milk in a moderate but clinically insignificant amount (Zhang 1997, Passmore 1988, Heisterberg 1983, Erickson 1981, Gray 1961).
No problems have been observed in infants whose mothers were taking it (Passmore 1988, Gray 1961), except for a possible case of diarrhea (Clements 1980).
Plasma levels of such infants are undetectable or very low (Passmore 1988, Gray 1961).

Metronidazole can redden body fluids and give a bitter or metallic taste to milk (Chin 2001, Andersson 1981), without this being harmful.

Although the opinions are divided (Huang 2016), being contraindicated for some (van der Woude 2015 and 2010, Nielsen 2014, m Yarur 2013), various medical societies, experts and consensus experts consider the use of this medication safe during breastfeeding ( Hale 2017 p 647, Schulze 2014, Kong 2013, Rowe 2013, Bar-Oz 2003, Einarson 2000, Rubin 1986), recommending some authors when the dose is large wait to breastfeed 12 to 24 hours after administration in order to minimize the exposure (Ladies 2015, Huang 2014, Rowe 2013, CDC 2010, WHO 2002).

In case of the mother of a premature or newborn, which metabolize worse metronidazole may be prudent, either use the minimum effective dose, or choose an alternative.

See below the information of this related product:


Very Low Risk

Compatible. Not risky for breastfeeding or infant.

Low Risk

Moderately safe. Mild risk possible. Follow up recommended. Read the Comment.

High Risk

Poorly safe. Evaluate carefully. Use a safer alternative. Read the Comment.

Very High Risk

Not recommended. Cessation of breastfeeding or alternative.


  • Metronidazole Benzoate
  • Metronidazole Hydrochloride


  • μετρονιδαζόλη (Greek)
  • ميترونيدازول (Arabic)
  • Метронидазол (Cyrillic)
  • 甲硝唑 (Chinese)
  • メトロニダゾール (Japanese)
  • C6 H9 N3 O3 (Molecular formula)
  • 2-(2-Methyl-5-nitroimidazol-1-yl)ethanol (Chemical name)
  • A01AB17; D06BX01; G01AF01; J01XD01; P01AB01 (ATC Code/s)


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  2. AEMPS-Sanofi. Metronidazol. Ficha técnica. 2018 Full text (in our servers)
  3. Huang VW, Chang HJ, Kroeker KI, Goodman KJ, Hegadoren KM, Dieleman LA, Fedorak RN. Management of Inflammatory Bowel Disease during Pregnancy and Breastfeeding Varies Widely: A Need for Further Education. Can J Gastroenterol Hepatol. 2016Abstract Full text (link to original source) Full text (in our servers)
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  6. FDA Hospira. Metronidazole.. Drug Summary. 2015 Full text (in our servers)
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