Mebendazole warnings and precautions
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Warnings and Precautions
Warnings
There is no evidence that mebendazole, even at high doses, is effective for hydatid disease. There have been rare reports of neutropenia and agranulocytosis when mebendazole was taken for prolonged periods and at dosages substantially above those recommended.
Precautions
General
Periodic assessment of organ system functions, including hematopoietic and hepatic, is advisable during prolonged therapy.
Information for Patients
Patients should be informed of the potential risk to the fetus in women taking mebendazole during pregnancy, especially during the first trimester (See Pregnancy).
Patients should also be informed that cleanliness is important to prevent reinfection and transmission of the infection.
Carcinogenesis, Mutagenesis, Impairment of Fertility
In carcinogenicity tests of mebendazole in mice and rats, no carcinogenic effects were seen at doses as high as 40 mg/kg (one to two times the human dose, based on mg/m2) given daily over two years. Dominant lethal mutation tests in mice showed no mutagenicity at single doses as high as 640 mg/kg (18 times the human dose, based on mg/m2). Neither the spermatocyte test, the F1 translocation test, nor the Ames test indicated mutagenic properties. Doses up to 40 mg/kg in mice (equal to the human dose, based on mg/m2), 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.
Pregnancy Category: C
Teratogenic Effects
Mebendazole has shown embryotoxic and teratogenic activity in pregnant rats at single oral doses as low as 10 mg/kg (approximately equal to the human dose, based on mg/m2). In view of these findings the use of mebendazole is not recommended in pregnant women. Although there are no adequate and well-controlled studies in pregnant women, a postmarketing 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.
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 considered.[1]
References
Adapted from the FDA Package Insert.