Ivermectin Dosing in Renal Impairment
No dose adjustment of ivermectin is required in patients with renal impairment, including those with severe renal failure. 1
Key Recommendation
The 2015 CDC Sexually Transmitted Diseases Treatment Guidelines explicitly state that adjustments to ivermectin dosing are not required in patients with renal impairment 1. This is the most authoritative guidance available for ivermectin use in the context of kidney function.
Standard Dosing Across All Renal Function Levels
- Normal renal function: 200 mcg/kg orally as a single dose 1, 2
- Mild-to-moderate renal impairment: 200 mcg/kg orally as a single dose (no adjustment needed) 1
- Severe renal failure: 200 mcg/kg orally as a single dose (no adjustment needed) 1
- End-stage renal disease/hemodialysis: 200 mcg/kg orally as a single dose (no adjustment needed) 1
Pharmacokinetic Rationale
Ivermectin's elimination profile supports this recommendation:
- Hepatic metabolism: Ivermectin is metabolized primarily in the liver by CYP3A4 2
- Fecal excretion: Ivermectin and its metabolites are excreted almost exclusively in feces over approximately 12 days 2
- Minimal renal clearance: Less than 1% of the administered dose is excreted in urine 2
This predominantly hepatic clearance pathway means renal function has minimal impact on drug elimination, eliminating the need for dose adjustments even in severe renal impairment.
Important Clinical Considerations
Dosing Frequency for Scabies
For scabies treatment, a second dose should be administered 14 days after the first dose regardless of renal function, as ivermectin has limited ovicidal activity 1.
Food Administration
Ivermectin should be taken with food to increase bioavailability (approximately 2.5-fold increase), which enhances penetration into the epidermis 1, 2. This contrasts with the FDA label recommendation for fasting administration for strongyloidiasis and onchocerciasis 2.
Hepatic Considerations
While no renal adjustment is needed, the safety of multiple doses in patients with severe liver disease is not known 1. Exercise caution in this population given the drug's hepatic metabolism.
Common Pitfall to Avoid
Do not confuse ivermectin with aminoglycosides or other renally-cleared antibiotics that require dose adjustment. The evidence clearly shows ivermectin follows a different elimination pathway and does not accumulate in renal impairment, making dose reduction unnecessary and potentially compromising efficacy.