Mebendazole is a broad-spectrum benzimidazole anthelmintic agent used primarily for the treatment of intestinal helminth infections. It acts by selectively and irreversibly inhibiting microtubule synthesis in parasitic cells, leading to glucose depletion and eventual death of the helminth. In the Indian context, it is a first-line treatment for common soil-transmitted helminthiases (STH) like ascariasis, trichuriasis, and hookworm infections, which are endemic in many regions due to poor sanitation.
Adult: For common STH (Ascaris, Trichuris, Hookworm): 100 mg twice daily for 3 consecutive days. For Enterobiasis (Pinworm): A single 100 mg dose, repeated after 2 weeks.
Note: Tablet can be chewed, swallowed whole, or crushed and mixed with food. For optimal absorption in systemic infections (off-label), administer with a high-fat meal. For intestinal infections, timing with food is less critical but can be taken with meals to reduce GI upset.
Mebendazole binds selectively and with high affinity to beta-tubulin of parasitic helminths, inhibiting its polymerization into microtubules. This disrupts the cytoplasmic microtubule network, which is essential for numerous cellular processes including glucose uptake, intracellular transport, and structural integrity.
Pregnancy: Category C (US FDA). Avoid in the first trimester. Use in second and third trimesters only if clearly needed and benefit outweighs risk. In India, it is generally avoided during pregnancy except in severe infestations under medical supervision.
Driving: May cause dizziness. Patients should not drive or operate machinery if they experience this effect.
| Carbamazepine, Phenytoin | Significantly reduces plasma levels of mebendazole via CYP450 induction, potentially reducing efficacy. | Major |
| Cimetidine | May increase plasma levels of mebendazole by inhibiting CYP450 metabolism. | Moderate |
| Metronidazole | Theoretical risk of Stevens-Johnson Syndrome; avoid concomitant use. | Major |
| Theophylline | Mebendazole may increase theophylline levels; monitor for toxicity. | Moderate |