CONTRAINDICATIONS AND PRECAUTIONS
Hypersensitivity to Mebendazole
Pregnancy (Mebendazole is a potent embryotoxin and teratogen{an agent or influence that causes physical defects in the developing embryo} in animals; effects may occur in pregnant rats at single oral doses of as low as 10 mg/kg. Thus, Mebendazole should not be given to pregnant women, nor is it advised in children less than 2 years of age)
Lactation (the period of milk secretion)
In treatment of children below two years, the benefits should be weighed against possible hazards.

ADVERSE REACTIONS
Are usually mild, consisting of:
Abdominal pain,
Nausea,
Diarrhea.
Mebendazole does not cause significant systemic toxicity in routine clinical use, even in the presence of anemia and malnutrition. This probably results from its low systemic bio-availability (the degree to which a drug or other substance becomes available to the target tissue after administration). Transient (temporary) symptoms of abdominal pain and diarrhea have occurred in case of massive infestation and expulsion of gastro-intestinal worms.
It should not be used in-patients who have experienced allergic reactions to the agent.