Promex

Approved Indications:

• Gastrointestinal Helminth Infections:
• Enterobiasis (pinworm)
• Ascariasis (roundworm)
• Trichuriasis (whipworm)
• Hookworm infections (Ancylostoma duodenale and Necator americanus)
• Strongyloidiasis (threadworm)
• Taeniasis (tapeworm)
• Mixed Helminth Infections:
• Effective against multiple simultaneous intestinal worm infestations.

Clinically Accepted Off-Label Uses:

• Hydatid Disease (Echinococcosis): Used as adjunctive therapy or when surgery is not feasible.
• Neurocysticercosis: In combination with corticosteroids and anticonvulsants.
• Toxocariasis (Visceral larva migrans): Occasionally used under specialist guidance.
• Giardiasis: As an alternative in select cases or resource-limited settings.

Route: Oral. Chewable tablets may be swallowed whole, chewed, or crushed.

Adults and Children ≥2 Years:

• Pinworm (Enterobiasis): 100 mg as a single dose; repeat after 2 to 3 weeks if reinfection is suspected.
• Roundworm, Whipworm, Hookworm: 100 mg twice daily for 3 consecutive days.
• Strongyloidiasis, Taeniasis: 200 mg twice daily for 3 days.
• Hydatid Disease (off-label): 40–50 mg/kg/day in divided doses for 3 to 6 months.
• Neurocysticercosis (off-label): 15–30 mg/kg/day (maximum 800 mg/day) for up to 30 days.

Children <2 Years:

• Not routinely recommended; may be used cautiously under medical supervision when clearly indicated.

Special Populations:

• Renal Impairment: No dose adjustment needed.
• Hepatic Impairment: Use with caution in moderate to severe impairment; monitor liver function in prolonged use.

Mebendazole acts by binding to the β-tubulin of parasitic worms, inhibiting microtubule polymerization. This disruption prevents glucose uptake and depletes the parasite's glycogen stores, leading to immobilization and eventual death. Its selective action within the gastrointestinal tract allows it to target intestinal parasites effectively while minimizing systemic toxicity.

• Absorption: Poorly absorbed from the gastrointestinal tract; systemic exposure is minimal.
• Distribution: High concentrations remain in the intestines; distributed to tissues with prolonged high-dose use.
• Metabolism: Undergoes extensive first-pass metabolism in the liver to inactive metabolites.
• Half-life: 2.5 to 5.5 hours.
• Excretion: Primarily via feces (unchanged); minor renal excretion as metabolites.
• Bioavailability: <10%; increases with fatty meals.

• Pregnancy: Former FDA Category C. Not recommended during the first trimester due to possible teratogenicity. Use only when benefits outweigh risks.
• Lactation: Small amounts are excreted in breast milk. Generally considered safe during breastfeeding, but caution is advised.

• Primary Class: Anthelmintic
• Subclass: Benzimidazole derivative

• Known hypersensitivity to mebendazole or any component of the formulation
• Use during the first trimester of pregnancy unless absolutely necessary
• Severe hepatic impairment (relative contraindication in long-term use)

• Hepatotoxicity: Monitor liver enzymes with prolonged or high-dose use.
• Neutropenia: Rare with long-term therapy; monitor CBC if used beyond recommended duration.
• Seizures: Very rarely reported, especially in pediatric patients or with high doses.
• Use in Young Children: Use with caution in children under 2 years due to limited safety data.

Common Adverse Effects (GI):

• Abdominal pain
• Nausea
• Diarrhea
• Flatulence

Central Nervous System:

• Headache
• Dizziness
• Rare: Seizures (mainly with high doses)

Hematologic (Prolonged Use):

• Neutropenia
• Agranulocytosis (rare)

Hepatic:

• Elevated liver transaminases

Dermatologic:

• Rash
• Urticaria
• Alopecia (rare, usually reversible)

Severity is generally mild; side effects are more likely with extended or high-dose treatment.

• Cimetidine: May increase mebendazole plasma concentrations by inhibiting hepatic metabolism.
• Phenytoin, Carbamazepine: May decrease mebendazole levels due to enzyme induction.
• Metronidazole: Concurrent use may increase risk of Stevens-Johnson syndrome—avoid co-administration.
• Fatty Meals: Enhance drug absorption; avoid high-fat meals if systemic effects are undesirable.
• Metabolism Involvement: CYP450 system (specific isoforms not well established).

• WHO: Continues to recommend mebendazole for preventive chemotherapy in children in high-risk areas.
• FDA & CDC: No recent changes in labeling or black box warnings.
• Public Health Programs: Remains widely used in mass deworming campaigns for soil-transmitted helminthiasis.

• Temperature: Store at or below 25°C (77°F).
• Humidity: Protect from moisture.
• Light: Store in a light-resistant container.
• Suspension: Shake well before use. Do not freeze.