Ivermectin

Ivermectin is a medication used to treat many types of parasite infestations. This includes head lice, scabies, river blindness (onchocerciasis), strongyloidiasis, trichuriasis, and lymphatic filariasis. It can be taken by mouth or applied to the skin for external infestations. Use in the eyes should be avoided. Common side effects include red eyes, dry skin, and burning skin. It is unclear if it is safe for use during pregnancy, but is likely acceptable for use during breastfeeding. It belongs to the avermectin family of medications. It works by causing the parasite's cell membrane to increase in permeability, resulting in paralysis and death. Ivermectin was discovered in 1975 and came into medical use in 1981. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The wholesale cost in the developing world is about US$0.12 for a course of treatment. In the United States, a 50ml bottle with about 25 doses, costs $25–50. In other animals it is used to prevent and treat heartworm among other diseases. Ivermectin is as effective as albendazole or alternative antinematode drugs for treatment of pinworm infection (enterobiasis). Ivermectin is used for prevention, treatment, and control of river blindness (onchocerciasis) in populations where the disease is common. However, ivermectin is contraindicated in persons with a high burden of loiasis (e.g., >20,000 Loa loa microfilariae per mL), due to risk of ivermectin-associated severe inflammatory events. A single dose of ivermectin reduces microfilaridermia by 98–99% after 1–2 months. Ivermectin does not kill adult worms. A single oral dose of ivermectin, taken once or twice a year for the 10–15-year lifespan of the adult worms, is required to protect the individual from river blindness. Moxidectin has been approved by the FDA for use in people with river blindness, has a longer half-life than ivermectin, and may eventually supplant ivermectin, as it is a more potent microfilaricide, but there is a need for additional clinical trials, with long-term follow-up, to assess whether moxidectin is safe and effective for treatment of nematode infection in children and women of childbearing potential. A single dose of ivermectin gives a rapid and durable decrease in body burden of eyeworm (Loa loa). The risk of ivermectin-associated severe adverse drug events is very low in persons with less than 20,000 microfilariae per mL of blood.