Combined Oral Ivermectin and 5% Permethrin Cream to Treat Severe Scabies.

Summary

In a blinded randomized trial of 132 adults with severe scabies, higher-dose ivermectin (400 μg/kg on days 0, 7, 14) plus 5% permethrin was not superior to standard-dose ivermectin (200 μg/kg) plus 5% permethrin. Cure occurred in 75% versus 82% (odds ratio 0.64; 95% CI, 0.25–1.67), with no safety signals.

Key Findings

• Higher-dose ivermectin (400 μg/kg) did not improve cure versus standard-dose (200 μg/kg) when both were combined with 5% permethrin.
• Cure rates were 75% (higher-dose) and 82% (standard-dose) with OR 0.64 (95% CI, 0.25–1.67).
• No safety issues were identified; the trial was registered (NCT02841215).

Clinical Implications

Use standard-dose ivermectin (200 μg/kg with food) plus 5% permethrin for severe scabies; avoid unnecessary dose escalation, reducing pill burden and potential toxicity while maintaining outcomes.

Limitations

• Moderate sample size may limit power to detect small differences
• Adults only; generalizability to pediatric or immunocompromised populations is uncertain

Future Directions

Evaluate alternative dosing intervals or adjunctive therapies in special populations (e.g., crusted scabies, immunosuppressed), and assess implementation and cost-effectiveness in endemic settings.