There is no evidence that VERMOX® (mebendazole), even at high doses, is effective for hydatid disease. There have been rare reports of neutropenia and agranulocytosis when VERMOX® was taken for prolonged periods and at dosages substantially above those recommended.
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 VERMOX® (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.
Drug Interactions: Preliminary evidence suggests that cimetidine inhibits mebendazole metabolism and may result in an increase in plasma concentrations of mebendazole.
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: Teratogenic effects. Pregnancy Category C. 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 VERMOX® is not recommended in pregnant women. Although there are no adequate and well-controlled studies in pregnant women, a post-marketing survey has been done of a limited number of women who inadvertently had consumed VERMOX® 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 VERMOX® was identified.
Nursing Mothers: It is not known whether VERMOX® is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when VERMOX® 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.