Treatment of Ascaris Lumbricoides Infection
The recommended first-line treatment for ascariasis is a single oral dose of albendazole 400 mg, mebendazole 500 mg, or ivermectin 200 μg/kg—all three options are highly effective with cure rates exceeding 95%. 1, 2
First-Line Medication Options
Choose any one of the following single-dose regimens:
- Albendazole 400 mg orally as a single dose 1, 2
- Mebendazole 500 mg orally as a single dose 1, 2
- Ivermectin 200 μg/kg orally as a single dose 1
All three medications demonstrate comparable efficacy with parasitological cure rates above 95% and egg reduction rates of 96-100%. 1, 3 The FDA label confirms mebendazole achieves a 98% cure rate for ascariasis. 4
Alternative Mebendazole Dosing
If using the FDA-labeled dosing regimen for mebendazole, administer one tablet (100 mg) twice daily (morning and evening) for 3 consecutive days. 4 However, the single 500 mg dose is equally effective and more convenient. 1, 2
Dosing Considerations
- The same dosage applies to both children and adults. 1, 4
- Tablets may be chewed, swallowed whole, or crushed and mixed with food. 4
- No fasting or purging is required before or after treatment. 4
Special Clinical Scenarios
Loeffler's Syndrome (Pulmonary Phase)
- Treat with albendazole 400 mg or mebendazole 500 mg as a single dose. 2
- Consider repeating treatment one month after resolution of pulmonary symptoms to ensure adult worms are eliminated, as initial treatment during larval migration may not affect all parasites. 2
- Exercise caution with corticosteroids if Strongyloides coinfection is possible. 2
Complicated Infections
- Intestinal or biliary obstruction may require surgical intervention in addition to anthelmintic therapy. 1
- For hyperinfestation syndrome, more aggressive treatment approaches may be necessary. 1
Follow-Up and Monitoring
- No specific follow-up is typically needed after successful treatment unless symptoms persist. 1
- If symptoms continue, repeat stool examination 2-3 weeks after treatment to confirm cure. 1
- If the patient is not cured three weeks after treatment, administer a second course. 4
Common Pitfalls to Avoid
- Do not assume treatment failure based solely on persistent mild symptoms—many resolve spontaneously after parasite clearance. 1
- In endemic areas with poor sanitation, reinfection is common and should not be confused with treatment failure. 1
- When treating Loeffler's syndrome, remember that symptoms may persist briefly even after successful treatment due to ongoing inflammatory response. 2
Safety Profile
All three medications are well-tolerated with minimal adverse events. 3 The most commonly reported side effects include nausea, vomiting, abdominal pain, diarrhea, headache, and fever, which are generally mild and self-limited. 3 No serious adverse events have been reported in clinical trials. 3