Mebendazole, its
fluorine analogue
flubendazole, and other
benzimidazole derivatives are active against many gastrointestinal and tissue-stage helminths. This article reviews the published literature and proceedings of a workshop on the use of
benzimidazoles against larval
echinococcosis (
hydatid disease). Orally administered high doses (30-50 mg/kg
body weight) of
mebendazole given daily for 20-90 days to rodents or sheep infected with larval Echinococcus granulosus cause damage of destruction of the
cyst wall, loss of cyst fluid, and death of protoscolices. Similar treatment of rodents infected with E. multilocularis with
mebendazole,
flubendazole,
fenbendazole, and
albendazole for 60-300 days leads to reduction of weight, inhibition of growth and the
metastases formation of E. multilocularis tissue, and to prolonged host survival time although the metacestodes are not killed.
Mebendazole or
flubendazole treatment of human patients infected with E. granulosus is followed by subjective improvement in most, and evidence of regression of
cysts in some; in other patients,
cysts continue to grow or have been proven viable even after several months of high-dose
mebendazole therapy. In patients infected with E. Multilocularis, the progressive course of the disease appeared to be arrested, but treatment apparently did not kill the parasite. Side effects of some patients have included
allergic reactions,
alopecia, and reversible
neutropenia. Some possible reasons for different responses to treatment include inadequate plasma
drug absorption from the gut and age, condition, and location of
cysts. Many remaining questions concerning the risk versus benefits of
mebendazole therapy can be answered only through controlled clinical trials.