Ivermectin Dosing Guidelines

Standard Dosing by Indication

• The Centers for Disease Control and Prevention recommends a dose of 200 mcg/kg orally, repeated in 2 weeks, for scabies treatment, which for a 56-kg patient equals four 3-mg tablets (12 mg total) as a single dose, then repeat in 14 days 1, 2
• For cutaneous larva migrans, the recommended dose is 200 mcg/kg as a single dose 2
• For pediculosis pubis (pubic lice), the recommended dose is 250 mcg/kg, repeated in 2 weeks 2
• For Loeffler's syndrome (empirical treatment), the recommended dose is 200 mcg/kg once daily for 3 days 3

Critical Administration Guidelines

• The Centers for Disease Control and Prevention recommends taking ivermectin with food to increase bioavailability and enhance drug penetration into the epidermis for scabies and most parasitic infections 1, 2

Special Population Considerations

• The American Academy of Pediatrics and the Centers for Disease Control and Prevention classify ivermectin as "human data suggest low risk" in pregnancy and is probably compatible with breastfeeding 1, 2
• For patients with renal impairment, no dose adjustments are required 1, 2
• For patients with hepatic impairment, ivermectin should be used with extreme caution in severe liver disease 1, 2, 4
• For pediatric patients, safety in children weighing <15 kg has not been determined, and children <10 years should not receive ivermectin for scabies; use permethrin instead 5

Common Pitfalls to Avoid

• Forgetting the second dose for scabies, as the 2-week repeat dose is mandatory due to limited ovicidal activity, as recommended by the Centers for Disease Control and Prevention 1, 2
• Incorrect food timing, as the specific indication requires food or fasting administration, according to the Centers for Disease Control and Prevention 1
• Using ivermectin in immunocompromised patients without specialist consultation, as one study showed increased mortality in elderly, debilitated persons, though not confirmed in subsequent reports, as noted by the Centers for Disease Control and Prevention 1
• Inadequate follow-up, as symptoms may persist for up to 2 weeks after successful scabies treatment due to allergic dermatitis, according to the Centers for Disease Control and Prevention 5
• Treating contacts, as for scabies, all household and sexual contacts within the previous month should be treated simultaneously, as recommended by the Centers for Disease Control and Prevention 1, 5

Ivermectin Dosing for Scabies

Special Considerations

• Ivermectin may cross the blood-brain barrier and cause neurotoxicity in young children, particularly those under 10 years old or weighing less than 15 kg, for whom permethrin 5% cream is recommended instead 6

Pediatric Considerations

• The American Academy of Pediatrics suggests that ivermectin should not be used in children weighing less than 15 kg or under 10 years old due to potential neurotoxicity, as evidenced by studies suggesting low risk in older children and adults 6

Treatment of Scabies with Ivermectin

Safety Considerations

• The American Academy of Pediatrics recommends avoiding lindane due to significant neurotoxicity risks, such as seizures and aplastic anemia, and instead suggests ivermectin as a safer alternative 7

Alternative Treatment Options

• For patients with crusted (Norwegian) scabies, especially if immunocompromised, consider intensive treatment with ivermectin 200 μg/kg on days 1, 2, 8, 9, and 15, plus daily topical permethrin, and requires specialist consultation 8, 9

Ivermectin Treatment Guidelines

Introduction to Ivermectin Dosage

• The American Academy of Pediatrics recommends 400 mcg/kg orally on day 1 and day 8 for head lice treatment, with food, as a non-FDA approved treatment option 10

Special Considerations for Ivermectin Use

• For loiasis, the CDC suggests maintaining microfilarial threshold below 8000 mf/ml when using ivermectin to reduce risk of severe adverse events, and considering albendazole or apheresis instead for higher loads 11, 12
• Children weighing less than 15 kg or under 10 years old have an absolute contraindication for ivermectin due to potential neurotoxicity, with the American Academy of Pediatrics recommending permethrin 5% cream as an alternative 10

Post-Treatment Care and Precautions

• The American Academy of Pediatrics notes that itching may persist for up to 2 weeks after successful scabies treatment due to allergic dermatitis, and recommends topical corticosteroids and oral antihistamines to relieve symptoms 10

Ivermectin Dosing for Parasitic Infections in Adults

Standard Dosing by Indication

• For immunocompetent patients with strongyloidiasis, a single dose of ivermectin is typically sufficient, according to the Journal of Infection 13
• For immunocompromised patients with strongyloidiasis, 200 mcg/kg on days 1, 2, 15, and 16 is recommended to prevent hyperinfection syndrome, as suggested by the Journal of Infection 13

Ivermectin Regimens Supported by Cited Evidence

Filarial Infections

• Onchocerciasis (river blindness) treatment – A regimen of 200 µg/kg ivermectin administered monthly for three consecutive months, combined with doxycycline 200 mg daily for six weeks, is recommended. After the initial course, ivermectin should be repeated every 3–6 months until the patient is asymptomatic, then given annually for several years as needed to maintain control of infection. 14

Skin Manifestations

• Cutaneous larva migrans – A single oral dose of 200 µg/kg ivermectin is effective for treating this skin infestation. 14