What is the recommended dose of ivermectin for treating scabies?

Ivermectin Dosing for Scabies Treatment

The recommended dose of ivermectin for treating scabies is 200 μg/kg (micrograms per kilogram) body weight, taken orally, with a second dose administered after 1-2 weeks to ensure complete eradication. 1

Dosing Protocol

• Initial dose: 200 μg/kg orally with food to increase bioavailability 1
• Second dose: Same dosage (200 μg/kg) administered 7-14 days after the first dose 1, 2
• Administration: Should be taken with food to enhance absorption 1

Treatment Efficacy

• Single dose efficacy: While a single dose can be effective in many cases, research shows that a second dose substantially improves cure rates 2
• The second dose is necessary because ivermectin may not be effective against all stages in the life cycle of the scabies mite, particularly the eggs 2

Special Populations and Considerations

Severe or Crusted Scabies

• For crusted (Norwegian) scabies, a combination approach is recommended:
  • Oral ivermectin at 200 μg/kg
  • Plus topical scabicides (typically 5% permethrin cream) 2
  • May require multiple doses of ivermectin

Children and Infants

• Traditional guidelines have cautioned against ivermectin use in children <15 kg 1
• However, emerging evidence supports the safety and efficacy of ivermectin in infants and children under 15 kg 3
• For children <15 kg, when used, the same dosage of 200 μg/kg has been studied with good safety profile 3
• Research indicates higher efficacy when the dose exceeds 200 μg/kg in this population 3

Pregnant or Lactating Women

• Permethrin 5% cream is preferred over oral ivermectin in pregnant or lactating women 1
• Safety data for ivermectin during pregnancy is limited

Additional Management Considerations

• Treat all household members and close contacts simultaneously, even if asymptomatic 1
• Decontaminate bedding and clothing by machine washing and drying using hot cycle 1
• Items that cannot be washed should be removed from body contact for at least 72 hours 1

Treatment Evaluation

• Evaluate after 1 week if symptoms persist 1
• Follow-up examinations should be performed to verify eradication 1
• If mites are still detected or no clinical improvement is observed, retreatment may be necessary 1

Common Pitfalls to Avoid

• Underdosing: Ensure accurate weight-based dosing at 200 μg/kg
• Missing the second dose: The second dose is crucial for complete eradication
• Failure to treat contacts: All household members and close contacts should be treated simultaneously to prevent reinfection
• Inadequate decontamination: Failure to properly clean bedding and clothing can lead to reinfection
• Ignoring persistent symptoms: If symptoms persist after treatment, reevaluation is necessary

Research has shown that a higher single dose of 400 μg/kg may be effective with a single administration 4, but current guidelines still recommend the standard 200 μg/kg dose with a second dose after 1-2 weeks 1, 2.