What are the off-label uses of Ivermectin and what are the recommended dosages?

Off-Label Uses of Ivermectin and Recommended Dosages

Ivermectin should not be used for off-label indications except for specific parasitic conditions, as there is insufficient evidence supporting its use for other conditions such as COVID-19 or cancer treatment. 1, 2

FDA-Approved Uses and Standard Dosing

Ivermectin is FDA-approved for only two conditions:

1. Strongyloidiasis: Single oral dose of 200 mcg/kg 3
2. Onchocerciasis: Single oral dose of 150 mcg/kg 3

Established Off-Label Uses and Dosing

1. Scabies

• Dosage: 200 mcg/kg orally, with a second dose typically given 7-10 days later 4, 5
• Evidence quality: Moderate; well-established in clinical practice
• Special populations:
  • In infants and children <15 kg: 200-223 mcg/kg has shown efficacy and safety 4
  • Higher efficacy observed when dose exceeds 200 mcg/kg and when second dose is given within 10 days 4

2. Demodex-Related Conditions

• Conditions: Blepharitis, demodicidosis, and rosacea
• Dosage: Variable depending on condition
• Evidence quality: Low to moderate; primarily based on clinical experience 5
• Note: Now FDA-approved for inflammatory lesions of rosacea (topical formulation)

Controversial Off-Label Uses (Not Recommended)

1. COVID-19

• Recommendation: Both the IDSA and multiple systematic reviews strongly recommend against using ivermectin for COVID-19 treatment 1, 6
• Evidence: Multiple RCTs have failed to demonstrate meaningful clinical benefit
  • In hospitalized patients: No proven effect on mortality or need for mechanical ventilation (RR: 0.54; 95% CI: 0.28,1.03) 1
  • In ambulatory patients: No proven effect on mortality (RR: 0.83; 95% CI: 0.50,1.37) 1

2. Cancer Treatment

• Recommendation: Not recommended for cancer treatment 2
• Evidence: Insufficient clinical evidence; research remains primarily preclinical
• Risks: May divert patients from proven cancer therapies 2

Safety Considerations for Off-Label Use

1. Mechanism of toxicity: Ivermectin binds to glutamate, GABA, and glycine receptors 7
2. Drug interactions: Caution with P-glycoprotein inhibitors which may increase neurotoxicity 7
3. Common adverse effects: Edema, rash, headache, and ocular complaints 7
4. Ethical considerations: Off-label prescribing during public health emergencies raises ethical concerns about evidence standards 8

Clinical Decision Algorithm for Off-Label Use

1. Confirm failure or contraindication to FDA-approved treatments
2. Verify evidence exists for the specific off-label indication
3. Ensure appropriate dosing based on condition and patient factors
4. Document informed consent discussing limited evidence and potential risks
5. Monitor for adverse effects

Key Pitfalls to Avoid

1. Dosing errors: Using doses higher than established safety thresholds
2. Inappropriate indications: Using for conditions with insufficient evidence
3. Self-medication: Patients obtaining veterinary formulations
4. Abandoning proven therapies: Especially critical in serious conditions like cancer or COVID-19

In summary, while ivermectin has established off-label use for certain parasitic conditions like scabies, its use for viral infections like COVID-19 or cancer treatment is not supported by current evidence and should be avoided.