What is the appropriate dosing for Ivermectin?

From the Guidelines

The appropriate dosing for Ivermectin is 200 ug/kg on days 1,2,8,9, and 15, with additional treatment on days 22 and 29 for severe cases, as recommended for crusted scabies treatment. This dosing regimen is based on the guidelines for treating crusted scabies, a condition that requires aggressive treatment due to its high transmission rate and potential for treatment failure with single-dose topical scabicides or oral ivermectin treatment 1. The treatment should be combined with a topical scabicide, either 5% topical benzyl benzoate or 5% topical permethrin cream, applied daily for 7 days and then twice weekly until discharge or cure.

• Key considerations for ivermectin dosing include:
  • The dose of 200 ug/kg is recommended for crusted scabies treatment, which may require multiple doses due to the severity of the condition
  • Ivermectin should be taken on an empty stomach with water, and tablets can be crushed for patients with difficulty swallowing
  • It is essential to follow the doctor's specific instructions, as dosing may vary based on individual factors, such as the condition being treated and the patient's overall health
  • Veterinary formulations of ivermectin should never be used for human treatment, as they may contain different concentrations or ingredients that are not safe for human use. The mechanism of action of ivermectin involves binding to glutamate-gated chloride channels in invertebrate nerve and muscle cells, leading to increased permeability to chloride ions, resulting in cellular hyperpolarization, paralysis, and death of the parasite 1.

From the FDA Drug Label

The patient should be reminded of the need for repeated stool examinations to document clearance of infection with Strongyloides stercoralis. Strongyloidiasis: The patient should be reminded that treatment with STROMECTOL does not kill the adult Onchocerca parasites, and therefore repeated follow-up and retreatment is usually required Based on this criterion, efficacy was significantly greater for STROMECTOL (a single dose of 170 to 200 mcg/kg) than for albendazole (200 mg b.i. d. for 3 days). STROMECTOL administered as a single dose of 200 mcg/kg for 1 day was as efficacious as thiabendazole administered at 25 mg/kg b.i.d. for 3 days.

The appropriate dosing for Ivermectin is a single dose of 170 to 200 mcg/kg for the treatment of strongyloidiasis 2.

• The dose may need to be repeated as follow-up and retreatment is usually required.
• Administration on an empty stomach with water is recommended 2.
• In immunocompromised patients, repeated courses of therapy may be required, with treatments possibly needed at 2-week intervals, and suppressive therapy may be helpful 2.

From the Research

Ivermectin Dosing

The appropriate dosing for Ivermectin varies depending on the condition being treated.

• For onchocerciasis, a single oral dose of 150 to 200 micrograms per kilogram of body weight is commonly used 3, 4, 5.
• A study suggests that 150 micrograms of ivermectin/kg may be the optimal dose for initial therapy 5.
• For scabies, a single oral dose of 200 micrograms per kilogram has been shown to be effective in otherwise healthy patients and in many patients with HIV infection 3.
• Higher doses of ivermectin, up to 2000 mcg/kg, have been used in some studies and have been found to be well tolerated and safe 6.
• An improved dosing schedule of 300 micrograms/kg has been suggested to reduce underdosing, with a proposed regimen of:
  • < 15 kg, 0 mg (0 tablet)
  • 15-20 kg, 6 mg (1 tablet)
  • 21-40 kg, 12 mg (2 tablets)
  • 41-60 kg, 18 mg (3 tablets)

  • 60 kg, 24 mg (4 tablets) 7

Dose-Finding Studies

Dose-finding studies have been conducted to determine the optimal dose of ivermectin for various conditions.

• A study found that a 3-day regimen of 600 mcg/kg/day achieved similar median maximum drug concentrations of ivermectin to a single dose of 800 mcg/kg, while increasing the median time above the lethal concentration 50% (LC50) from 1.9 days to 6.8 days 6.
• Another study found that a single dose of 200 micrograms/kg was effective in reducing ocular microfilaria load for at least 12 months, with minimal systemic and ocular side effects 4.