Mebendazole

Class

• Benzimidazole antihelmintic

Indications

• Nematode infections

  • Pinworms, roundworms, tapeworms, hookworms, whipworms

Administration/Absorption

• Oral

• Poorly absorbed (approximately 5 to 10%) from gastrointestinal tract

  • Fatty food increases absorption

Dosage

• Pinworms: 100 mg once

• Whipworm, common roundworm and hookworm: 100 mg BD for 3 days

Distribution

• 90-95% protein bound

Mechanism

• Selectively inhibits the synthesis of microtubules in parasitic worms

  • => destroys extant cytoplasmic microtubes in their intestinal cells

• Thereby blocks the uptake of glucose and other nutrients

• Results in the gradual immobilization and eventual death of the helminths

Excretion

• Primarily hepatic metabolism

• Half life 2.5 to 5.5 hours

Side effects

• Transient abdominal pain, diarrhea, slight headache, fever, dizziness, exanthema, urticaria and angioedema

Interactions

• Carbamazepine and phenytoin lower serum levels of mebendazole

• Stevens–Johnson syndrome can occur when mebendazole is combined with high doses of metronidazole

Contraindications

• Pregnancy

  • Embryotoxic and teratogenic in experimental animals