Mebendazole
A benzimidazole anthelmintic, often a chewable tablet, for threadworm, roundworm, whipworm and hookworm in the gut.
Drug card
- How it works
- Binding worm β-tubulin so microtubules cannot form and glucose uptake fails
- Used for
- Threadworm (pinworm) infection
- Roundworm, whipworm and hookworm infections
- Known for
- Abdominal pain or discomfort
- Its name
- -bendazole means a benzimidazole anthelmintic
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does mebendazole work?
Mebendazole binds worm β-tubulin and disrupts microtubule formation, damaging the worm's intestinal cells so it cannot take up glucose; it is immobilized, stops producing eggs and dies. Most of the dose stays in the gut, where it acts; only a little is absorbed, more after a high-fat meal.
Like other benzimidazole anthelmintics: Benzimidazoles bind β-tubulin in worm cells, at its colchicine-sensitive site, and stop it polymerizing into microtubules. Without microtubules the worm's intestinal cells cannot take up glucose, glycogen stores run down, ATP runs short, and the worm is immobilized and dies. Mebendazole stays mostly in the gut; albendazole is poorly absorbed too, but its active sulfoxide metabolite reaches tissue cysts.
Uses
What is mebendazole used for?
- Threadworm (pinworm) infection
- Roundworm, whipworm and hookworm infections
Side effects
Side effects of mebendazole
- Abdominal pain or discomfortKnown for
- Diarrhea
- Nausea and vomiting
- Loss of appetite
- Rash
- Neutropenia and agranulocytosis at high dosesSerious
- Seizures in infants under 1 yearSerious
- Hepatitis and abnormal liver testsSerious
- SJS and TEN, mainly with metronidazoleSerious
- Anaphylaxis and angioedemaSerious
- Hair loss
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Avoid with metronidazole: the combination has been linked to SJS and TEN.
- Check blood counts if it is used at high doses or for long periods.
- Convulsions have been reported in infants under 1 year.
- In pregnancy it is used only if benefits outweigh risks; hygiene measures come first, especially early on.
Good to know: Acts almost only in the gut, which suits intestinal worms; for tapeworm cysts in tissues, albendazole is used instead. WHO lists both for mass deworming.
Remember it
A way to remember it
Benzimidazoles starve the worm: no microtubules, no glucose.
By stopping β-tubulin from forming microtubules, they leave the worm's gut cells unable to take up glucose; its glycogen and ATP run out and it dies.
Written for biofideX
Its name
-bendazole means benzimidazole anthelmintic
Albendazole and mebendazole stop worms building microtubules. Omeprazole is also a benzimidazole but ends in -prazole.
- Every drug name stem
Its class
Benzimidazole anthelmintics
Other benzimidazole anthelmintics with a card:
Easily mixed up with avermectins, azole antifungals and colchicine.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Mebendazole chewable tablet: label (DailyMed)
- Mebendazole (NCI Thesaurus)
- Mebendazole (NHS)
- Soil-transmitted helminth infections (WHO)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Antifungals and antiparasitics
Mebendazole is one of 14 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
Start Practicing