Is ivermectin associated with liver toxicity?

Ivermectin and Liver Toxicity

Ivermectin can cause hepatotoxicity, though it is rare with standard therapeutic doses, and caution is warranted in patients with pre-existing liver disease. 1, 2

Hepatotoxicity Risk Profile

Evidence of Liver Toxicity

• Hepatotoxicity has been documented in case reports, including cases of:
  • Cytolysis (elevated liver enzymes) 3
  • Severe hepatitis requiring liver biopsy 4
  • Abnormal liver function tests 2

Risk Factors

• Pre-existing liver disease 5
• Elderly patients may be at higher risk 3
• Higher or repeated dosing may increase risk
• Drug interactions that affect metabolism, particularly:
  • Azithromycin can significantly increase serum ivermectin concentration 5
  • CYP3A4 inhibitors like ketoconazole may increase ivermectin levels 6

Monitoring Recommendations

Before Treatment

• Assess baseline liver function in patients with:
  • History of liver disease
  • Concomitant hepatotoxic medications
  • Planned long-term or high-dose therapy

During Treatment

• Monitor for symptoms of hepatotoxicity:
  • Nausea, vomiting, abdominal pain
  • Jaundice
  • Fatigue
• Consider liver function tests if:
  • Symptoms develop
  • Patient has pre-existing liver disease
  • Treatment is prolonged

Clinical Management

Dosing Considerations

• Standard dosing (200 μg/kg) appears to have minimal hepatotoxicity risk in healthy individuals 1
• Caution is advised in patients with reduced hepatic function 5
• The safety of multiple doses in patients with severe hepatic disease is not well established 1

Drug Interactions

• Avoid concomitant use with:
  • Azithromycin (increases ivermectin concentration) 5
  • Other hepatotoxic medications when possible
  • CYP3A4 inhibitors may increase ivermectin levels and potential toxicity 6

If Hepatotoxicity Occurs

• Discontinue ivermectin immediately
• Monitor liver function until normalization
• Consider alternative treatments
• Most cases of hepatotoxicity resolve within weeks after discontinuation 3

Special Populations

Patients with Liver Disease

• Use with caution in patients with reduced hepatic function 5
• Consider dose adjustment or alternative treatments in severe liver disease

Pregnancy and Breastfeeding

• Ivermectin is generally considered compatible with breastfeeding 5, 1
• Low concentration excretion in breast milk means amounts ingested by the infant are likely to be small 5

Clinical Perspective

While ivermectin-induced hepatotoxicity is uncommon, clinicians should be aware of this potential adverse effect, particularly when prescribing to patients with pre-existing liver conditions or those taking medications that may interact with ivermectin's metabolism. The benefit-risk profile remains favorable for standard indications at recommended doses, but monitoring may be appropriate in high-risk patients or with extended treatment courses.