Mebendazole is contraindicated in persons who have shown hypersensitivity to the drug.
There is no evidence that mebendazole, even at high doses, is effective for hydatid
disease. There have been rare reports of neutropenia and liver function elevations,
including hepatitis, when mebendazole is taken for prolonged periods and at dosages
substantially above those recommended.
Information for the Patient: Patients should be informed of the potential risk to the fetus
in women taking mebendazole during pregnancy, especially during the first trimester (see
Use in Pregnancy).
Patients should also be informed that cleanliness is important to prevent reinfection and
transmission of the infection.
Carcinogenesis, Mutagenesis: In carcinogenicity tests of mebendazole in mice and rats,
no carcinogenic effects were seen at doses as high as 40 mg/kg given daily over two
years. Dominant lethal mutation tests in mice showed no mutagenicity at single doses as
high as 640 mg/kg. Neither the spermatocyte test, the F1 translocation test, not the Ames
test indicated mutagenic properties.
Impairment Fertility: Doses up to 40 mg/kg in mice, given to males for 60 days and to
females for 14 days prior to gestation, had no effect upon fetuses and offspring, though
there was slight maternal toxicity.
Usage in Pregnancy: Pregnancy Category C. Mebendazole has shown embryotoxic
and teratogenic activity in pregnant rats at single oral doses as low as 10 mg/kg. In view
of these findings the use of mebendazole is not recommended in pregnant women. In
humans, a post-marketing survey has been done of a limited number of women who
inadvertently had consumed mebendazole during the first trimester of pregnancy. The
incidence of spontaneous abortion and malformation did not exceed that in the general
population. In 170 deliveries on term, no teratogenic risk of mebendazole was identified.
During pregnancy, especially during the first trimester, mebendazole should be used only
if the potential benefit justifies the potential risk to the fetus.
Nursing Mothers: It is not known whether mebendazole is excreted in human milk.
Because many drugs are excreted in human milk, caution should be exercised when
mebendazole is administered to a nursing woman.
Pediatric Use: The drug has not been extensively studied in children under two years;
therefore, in the treatment of children under two years the relative benefit/risk should be