Mebendazole

A benzimidazole that acts by interfering with carbohydrate metabolism and inhibiting polymerization of microtubules. [PubChem]

Mebendazole is a benzimidazole anthelmintic used to treat helminth infections.

For the treatment of Enterobius vermicularis (pinworm), Trichuris trichiura (whipworm), Ascaris lumbricoides (common roundworm), Ancylostoma duodenale (common hookworm), Necator americanus (American hookworm) in single or mixed infections.

• Ancylostoma caninum infection
• Ancylostoma duodenale infection
• Ascaris lumbricoides infection
• Capillariasis
• Enterobius vermicularis infection
• Filariasis
• Giardiasis
• Necatoriasis due to necator americanus
• Strongyloides Stercoralis Infection
• Taenia solium infection
• Toxocariasis
• Whipworm infection

Mebendazole is a (synthetic) broad-spectrum anthelmintic. The principal mode of action for Mebendazole is by its inhibitory effect on tubulin polymerization which results in the loss of cytoplasmic microtubules.

Mebendazole causes degenerative alterations in the tegument and intestinal cells of the worm by binding to the colchicine-sensitive site of tubulin, thus inhibiting its polymerization or assembly into microtubules. The loss of the cytoplasmic microtubules leads to impaired uptake of glucose by the larval and adult stages of the susceptible parasites, and depletes their glycogen stores. Degenerative changes in the endoplasmic reticulum, the mitochondria of the germinal layer, and the subsequent release of lysosomes result in decreased production of adenosine triphosphate (ATP), which is the energy required for the survival of the helminth. Due to diminished energy production, the parasite is immobilized and eventually dies.

Poorly absorbed (approximately 5 to 10%) from gastrointestinal tract. Fatty food increases absorption.

90-95%

In man, approximately 2% of administered mebendazole is excreted in urine and the remainder in the feces as unchanged drug or a primary metabolite.

2.5 to 5.5 hours (range 2.5 to 9 hours) in patients with normal hepatic function. Approximately 35 hours in patients with impaired hepatic function (cholestasis).

Acute oral toxicity (LD₅₀): 620 mg/kg [Mouse]. Symptoms of overdose include elevated liver enzymes, headaches, hair loss, low levels of white blood cells (neutropenia), fever, and itching.

• Take with or without food.

• Threadworms: 100 mg or 1 teaspoonful: Single dose.
• Whipworms, Roundworms, Hookworms: 100 mg or 1 teaspoonful: Twice daily for 3 days.