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Anthelmintic (benzimidazole) Pregnancy: Contraindicated — animal teratogenicity (skeletal malformations). Confirm negative pregnancy test before start; effective contraception during and 1 month after treatment.

Albendazole

Brand names: Eskazole, Zentel, Albenza

Adult dose

Dose: Threadworm: 400 mg single dose (repeat after 2 weeks). Hookworm/Ascaris/Trichuris: 400 mg single dose. Strongyloides: 400 mg BD for 3 days. Hydatid disease (cystic echinococcosis): 400 mg BD with food for 28 days, repeat after 14-day break (3 cycles, often longer for hepatic disease). Neurocysticercosis: 400 mg BD with food for 8–30 days (always with corticosteroids).
Route: Oral
Frequency: Once or twice daily depending on indication
Max: 800 mg/day for systemic infections
Take with fatty meal to enhance absorption (essential for systemic infections — hydatid, cysticercosis).

Paediatric dose

Dose: 15 mg/kg
Route: Oral
Frequency: BD (split dose)
Max: 800 mg/day
Children ≥6 years (≥10kg). Threadworm/Ascaris: 400 mg single dose if ≥2 yrs (or 200 mg if 1–2 yrs — limited data). Hydatid/neurocysticercosis: 15 mg/kg/day in 2 divided doses, max 800 mg/day, with food.
Paediatric weight-based calculator

Children ≥6 years (≥10kg). Threadworm/Ascaris: 400 mg single dose if ≥2 yrs (or 200 mg if 1–2 yrs — limited data). Hydatid/neurocysticercosis: 15 mg/kg/day in 2 divided doses, max 800 mg/day, with food.

Clinical pearls

  • Pre-treat neurocysticercosis with corticosteroids (dexamethasone 6–24 mg/day) to prevent inflammatory worsening as cysts die.
  • Always co-prescribe an anti-epileptic if neurocysticercosis presents with seizures.
  • For hydatid disease, surgical / PAIR (puncture, aspiration, injection, reaspiration) approach often combined with peri-procedural albendazole — specialist hepatobiliary/ID input.
  • FBC and LFTs weekly in long systemic courses; stop if neutrophils <1.0 or transaminases >5× ULN.
  • Far more effective than mebendazole for systemic infections due to better absorption when taken with fat.

Contraindications

  • Pregnancy (especially 1st trimester — animal teratogenicity)
  • Hypersensitivity to benzimidazoles
  • Pre-existing severe hepatic impairment or cytopenia (relative)

Side effects

  • Hepatotoxicity (raised transaminases — common in long courses) — monitor LFTs
  • Bone marrow suppression: leukopenia, thrombocytopenia, aplastic anaemia (rare but serious)
  • Headache, dizziness, raised ICP (in neurocysticercosis — pre-treat with corticosteroids)
  • GI upset: nausea, abdominal pain, diarrhoea
  • Alopecia (reversible)
  • Allergic reactions, fever
  • Cyst rupture in hydatid (anaphylaxis risk)

Interactions

  • Cimetidine: ↑ albendazole levels (may be useful in CNS disease)
  • Dexamethasone: ↑ plasma albendazole (often co-prescribed in neurocysticercosis)
  • Phenytoin / carbamazepine / phenobarbital: ↓ albendazole levels (CYP induction)
  • Ritonavir: ↓ albendazole levels

Monitoring

  • FBC weekly during prolonged courses
  • LFTs weekly during prolonged courses; baseline then 4-weekly
  • Pregnancy test before initiation in women of childbearing potential

Reference: BNFc; BNF 90; BNF for Children 2024; WHO Guidelines on Echinococcosis 2009 / 2022 update; CDC Parasitic Disease Treatment Guidance; NICE CKS Worms. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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