What is the recommended treatment for Strongyloides infection?

Treatment of Strongyloides Infection

Ivermectin 200 μg/kg orally for 2 consecutive days is the recommended treatment for uncomplicated strongyloidiasis, providing cure rates of 77-100% with excellent tolerability. 1, 2

Standard Treatment Regimen

• Administer ivermectin 200 μg/kg orally on 2 consecutive days for immunocompetent patients with chronic strongyloidiasis 1, 2
• Take tablets on an empty stomach with water to optimize absorption 2
• This 2-day regimen achieves 100% cure rates compared to 77-83% with single-dose therapy 3
• The FDA-approved dosing is a single dose of 200 μg/kg, though clinical evidence supports the 2-day regimen for higher efficacy 2, 3

Weight-based dosing (for 200 μg/kg): 2

• 15-24 kg: 1 tablet (3 mg)
• 25-35 kg: 2 tablets (6 mg)
• 36-50 kg: 3 tablets (9 mg)
• 51-65 kg: 4 tablets (12 mg)
• 66-79 kg: 5 tablets (15 mg)
• ≥80 kg: 200 μg/kg

Immunocompromised Patients

For immunocompromised patients or those requiring immunosuppressive therapy, use ivermectin 200 μg/kg on days 1,2,15, and 16 to prevent hyperinfection syndrome 1, 4

• This extended regimen addresses the risk of autoinfection cycles in patients with impaired immunity 1
• Screen and treat all patients before initiating corticosteroids or other immunosuppressive therapy, as failure to do so can precipitate fatal hyperinfection syndrome 1, 4
• Consider empiric treatment for patients from endemic areas who will receive immunosuppression, even without confirmed diagnosis 1

Critical Warning: Hyperinfection Syndrome

Never initiate corticosteroid therapy without first treating strongyloidiasis - this can trigger potentially fatal hyperinfection syndrome with gastrointestinal bleeding, pneumonia, sepsis, or meningitis 1, 4

• Patients receiving corticosteroids or immunosuppressive therapy must be screened and treated prophylactically 1, 4
• Monitor for symptoms of hyperinfection including severe abdominal pain, bloody diarrhea, respiratory distress, or altered mental status 1

Alternative Treatment (Less Effective)

• Albendazole 400 mg daily for 3 days is an alternative but achieves only 38-63% cure rates compared to ivermectin's superior efficacy 1, 5
• Reserve albendazole for situations where ivermectin is contraindicated or unavailable 1

Follow-up and Monitoring

• Perform stool examinations at 2 weeks, 1 month, and 3 months post-treatment to verify eradication, as recrudescence can occur up to 106 days after therapy 2
• Use concentration techniques (Baermann apparatus) for stool examination, as larval counts may be very low 2
• At least three stool examinations over three months are necessary to confirm cure 2
• If larvae reappear, retreat with ivermectin using the same dosing regimen 2
• Persistent eosinophilia after treatment suggests treatment failure in 77% of cases 3

Clinical Context

• The most recent high-quality trial (2019, Lancet Infectious Diseases) found that single-dose ivermectin achieved 86% cure rates at 12 months, with no superiority demonstrated for multiple doses in immunocompetent patients 6
• However, the 2-day consecutive dosing regimen (not the extended 4-dose regimen) consistently shows 100% cure rates in clinical practice 3
• For immunocompetent patients, use the 2-day consecutive regimen; for immunocompromised patients, use the extended 4-dose regimen on days 1,2,15, and 16 1, 3

Safety Profile

• Ivermectin is well-tolerated with minimal adverse effects (primarily mild dizziness or dyspepsia in <10% of patients) 3
• Adverse events are generally mild and self-limited 6
• The drug has a plasma half-life of approximately 18 hours and is metabolized by CYP3A4 2