What is the recommended albendazole dose for deworming in adults and in children (≤15 kg vs >15 kg), and what are the contraindications?

Albendazole for Deworming: Dosing and Contraindications

Standard Dosing Recommendations

For intestinal helminth infections, albendazole 400 mg as a single oral dose is the standard treatment for both adults and children over 24 months of age, with repeat dosing at 2 weeks required for pinworm and hookworm infections. 1, 2

Adult Dosing

• Single-dose regimen: Albendazole 400 mg orally once for ascariasis, hookworm, and pinworm 3, 1
• Extended regimens:
  • Hookworm: 400 mg daily for 3 days 1
  • Whipworm (Trichuris): 400 mg daily for 3 days 1
  • Strongyloidiasis: 400 mg daily for 3 days, with repeat course at 8 weeks 2
  • Pinworm: 400 mg single dose, repeated in 2 weeks 1, 4

Pediatric Dosing by Weight/Age

Children >15 kg (typically >24 months):

• Standard adult dose of 400 mg applies for single-dose regimens 1, 2
• Same extended regimens as adults for specific parasites 2

Children ≤15 kg (typically 12-24 months):

• Albendazole 400 mg can be used for ascariasis or trichuriasis when epidemiology justifies treatment 2
• Expert consultation is required before empirical treatment of asymptomatic eosinophilia in this age group 3, 2
• Not recommended for infants <12 months except for life-threatening infections under specialist guidance 2

Critical Administration Requirements

Albendazole must always be administered with food, preferably fatty meals, to maximize absorption. 1 This is essential because albendazole is poorly absorbed on an empty stomach. 3

• Avoid liquid paraffin (mineral oil) during treatment as it significantly impairs absorption 1

Contraindications and Pre-Treatment Screening

Absolute Requirements Before Treatment

1. Fundoscopic examination must be performed to detect retinal cysticercosis before initiating therapy 1
2. Exclude Loa loa infection in patients from endemic regions (Central/West Africa) before administering combination therapy with ivermectin 3, 1, 2
3. Screen for Strongyloides stercoralis in patients requiring prolonged corticosteroids, as hyperinfection syndrome can be fatal 1

Relative Contraindications

• Pregnancy: Use only when benefit clearly outweighs risk 3
• Active hepatic disease: Albendazole can cause hepatotoxicity 3
• Pre-existing leukopenia: Monitor closely as albendazole causes leukopenia in up to 10% of patients 3, 1

Monitoring Requirements

For treatment courses >14 days:

• Complete blood count at the beginning of each 28-day cycle and every 2 weeks during therapy 3, 1
• Liver enzymes (transaminases) at the beginning of each cycle and at least every 2 weeks 1
• Elevated liver enzymes occur in up to 16% of patients on chronic therapy, requiring discontinuation in 3.8% 3

For single-dose or short courses (<14 days):

• No routine laboratory monitoring required 3, 1

Important Clinical Pitfalls

Repeat Dosing Considerations

• Schistosomiasis: Eggs and immature schistosomulae are relatively resistant; repeat treatment at 8 weeks is necessary 3
• Pinworm: Always repeat dose at 2 weeks to eradicate newly hatched worms 1, 4
• Hookworm: Consider repeat dosing at 2 weeks for optimal cure rates 1

Drug-Specific Efficacy Expectations

Research demonstrates that single-dose albendazole achieves:

• Ascariasis: 95-98% cure rate 5, 6, 7, 8
• Hookworm: 78-88% cure rate (higher for A. duodenale at 92%, lower for N. americanus at 75%) 5, 6, 8
• Whipworm: Only 46-48% cure rate with single dose—extended 3-day regimen required 5, 6, 8
• Pinworm: 98-100% cure rate with repeat dosing 7, 8

Treatment Failure vs. Reinfection

• Persistent symptoms after treatment usually indicate reinfection rather than drug resistance 4
• True treatment failure is rare; consider alternative diagnosis or reinfection from household contacts 4

Special Populations

Empirical Treatment for Eosinophilia

For asymptomatic eosinophilia with negative stool microscopy in patients >24 months:

• Albendazole 400 mg single dose plus ivermectin 200 μg/kg 3, 1
• This combination treats possible prepatent or undetected geohelminth infections 3
• Must exclude Loa loa before ivermectin administration 3, 1

Immunocompromised Patients

• For microsporidiosis (Encephalitozoon intestinalis): Albendazole 7.5 mg/kg orally twice daily (maximum 400 mg twice daily) for patients <60 kg 1
• Seek specialist advice for all immunocompromised patients 3