What are the treatments for parasitic infections?

From the Guidelines

For treating parasitic infections, albendazole is a highly effective treatment option, with a recommended dosage of 15 mg/kg/day in twice-daily doses for 1–2 weeks, as suggested by the 2018 clinical practice guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH) 1.

Treatment Options

The treatment approach depends on the specific parasite involved, with different medications and dosages recommended for various types of parasitic infections.

• For intestinal parasites like roundworms, pinworms, and hookworms, albendazole (400mg as a single dose for adults) or mebendazole (100mg twice daily for 3 days) are effective first-line treatments.
• For giardiasis, metronidazole (250mg three times daily for 5-7 days) or tinidazole (2g single dose) work well.
• Malaria requires specific antimalarial medications like chloroquine, artemisinin-based combination therapies, or atovaquone-proguanil, with dosing based on weight and region-specific resistance patterns.

Importance of Completing Treatment

When treating parasites, it's essential to complete the full course of medication even if symptoms improve, as this helps prevent reinfection and ensures the parasite is fully eliminated from the body.

Preventing Reinfection

Family members or close contacts may need simultaneous treatment for certain parasites like pinworms to prevent reinfection. Good hygiene practices, including handwashing, proper food preparation, and clean drinking water, are also crucial in preventing reinfection.

Mechanism of Action

These medications work by either paralyzing the parasites, disrupting their metabolic processes, or interfering with their ability to reproduce, allowing the body to eliminate them naturally. According to a study published in 2010, ivermectin (200 mg/kg as a single dose) or albendazole (400 mg od 3 days) can be used to treat cutaneous larva migrans, a parasitic infection that can cause skin symptoms like itch and urticaria 1. Another study from 2004 recommends albendazole for the treatment of microsporidia infection, with a dosage of 7.5 mg/kg orally twice daily for persons weighing less than 60 kg, and a maximum dose of 400 mg orally twice daily 1.

From the FDA Drug Label

STROMECTOL is indicated for the treatment of the following infections: Strongyloidiasis of the intestinal tract. STROMECTOL is indicated for the treatment of intestinal (i.e., nondisseminated) strongyloidiasis due to the nematode parasite Strongyloides stercoralis. STROMECTOL is indicated for the treatment of onchocerciasis due to the nematode parasite Onchocerca volvulus.

The treatments for parasitic infections include:

• Ivermectin (PO) for the treatment of:
  • Strongyloidiasis of the intestinal tract
  • Onchocerciasis due to the nematode parasite Onchocerca volvulus
• Surgical excision of subcutaneous nodules (nodulectomy) may be considered in the management of patients with onchocerciasis to eliminate the microfilariae-producing adult parasites 2

From the Research

Treatments for Parasitic Infections

• The current first-choice therapy for giardiasis is metronidazole, but other drugs such as tinidazole and albendazole have shown potential in treating the infection 3.
• Tinidazole has been associated with higher parasitological cure rates compared to metronidazole and albendazole, making it a potentially more effective treatment option 3, 4, 5.
• Albendazole has been shown to be effective in treating intestinal helminthiasis and controlling the recurrence of hookworm infections, with a single dose of 400mg per day for 3 or 5 days demonstrating good effect 6.
• Ivermectin, a broad-spectrum antiparasitic agent, has been found to be effective against combined intestinal protozoal infection (giardiasis and cryptosporidiosis) at a dose of 200 micrograms/kg 7.
• A meta-analysis comparing the efficacy of albendazole and tinidazole in treating Giardia infections in children found that tinidazole significantly outperformed albendazole, with a relative risk of 1.61 (95% CI: 1.40-1.85) 5.

Comparison of Treatment Options

• Tinidazole has been found to have a higher efficacy rate compared to albendazole in treating Giardia infections in children, with a number-needed-to-treat of 4 (95% CI: 3-5) 5.
• Metronidazole has been associated with significant failure rates in clearing parasites from the gut, and its use is often limited by poor compliance due to side effects 5.
• Albendazole has been shown to be effective in treating intestinal helminthiasis, but its efficacy in treating Giardia infections is lower compared to tinidazole 3, 6, 5.