Mebendazole use while Breastfeeding
Drugs containing Mebendazole: Vermox
Mebendazole Levels and Effects while Breastfeeding
Summary of Use during Lactation
Limited data indicate that mebendazole is poorly excreted into breastmilk. Because mebendazole is virtually unabsorbed orally it is unlikely to adversely affect the breastfed infant or milk production. An informal consultation group to the World Health Organization concluded that a single oral dose of mebendazozle can be given to lactating women.
Maternal Levels. One author reported information received by personal communication from the manufacturer stating that after a single 100 mg oral dose of mebendazole to a nursing mother (time postpartum not stated), the peak milk level was 6 mcg/L. Mebendazole was no longer detectable (<1 mcg/L) in milk 13.25 hours after the dose.
One woman was given mebendazole 100 mg orally twice daily for 3 days beginning the first day postpartum. Mebendazole was measured in milk following treatment (exact timing not stated). Mebendazole was undetectable (<20 mcg/L) in milk. The authors stated that this value was in agreement with those reported by the manufacturer and that the infant probably absorbed negligible mebendazole from breastmilk.
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.
Effects on Lactation and Breastmilk
A nursing mother who was 13 weeks postpartum was taking oral metronidazole 250 mg three times daily. Milk production seemed to be unaffected. On the eighth day of therapy she passed a roundworm. Metronidazole was discontinued and oral mebendazole 100 mg twice daily was started. The patient was "tense" for a few days after passing the worm. On the second day of mebendazole treatment, milk production dropped markedly and she began supplementation with formula. By day 7, milk production had ceased. The authors suggested that mebendazole might have caused the drop in milk production, but offered no further evidence other than the temporal relationship.
Four patients were treated with oral mebendazole 100 mg twice daily for 3 days beginning the first day postpartum. Two had pinworm (Enterobius), 1 had roundworm (Ascaris) and 1 had hookworm (Ancyclostomia) infestations. All breastfed successfully.
One author reported information received by personal communication from the manufacturer stating that no inhibition of lactation was noted after a single 100 mg oral dose of mebendazole to a nursing mother (time postpartum not stated).
Alternate Drugs to Consider
1. Allen HE, Crompton DW, de Silva N et al. New policies for using anthelmintics in high risk groups. Trends Parasitol. 2002;18:381-2. PMID: 12377247
2. Stoukides C. Can a mother safely breastfeed while on mebendazole (Vermox)? J Hum Lact. 1994;10:269. PMID: 7619284
3. Kurzel RB, Toot PJ et al. Mebendazole and postpartum lactation. N Z Med J. 1994;107:439. Letter. PMID: 7970347
4. Rao TS. Does mebendazole inhibit lactation? N Z Med J. 1983;96:589-90. Letter . PMID: 6575310
CAS Registry Number
LactMed Record Number
Last Revision Date
Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.