Ivermectin is an antiparasitic medication used to treat a variety of parasitic infections in humans and animals. It was discovered in 1975 and initially used in veterinary medicine to prevent and treat parasites such as heartworm and acariasis in animals

. In humans, ivermectin is approved to treat infections caused by parasitic worms and external parasites. It is effective against conditions including:

• Onchocerciasis (river blindness), caused by parasitic worms transmitted by blackfly bites
• Strongyloidiasis, an intestinal infection from contact with contaminated soil
• Other worm infections such as ascariasis, trichuriasis, and enterobiasis
• External infestations like head lice and scabies

Ivermectin works by binding to specific chloride ion channels in the nerve and muscle cells of parasites, causing paralysis and death of the parasites. It interferes with nerve and muscle function, effectively killing the worms or parasites

. The drug is available in oral tablet form for internal infections and topical formulations for external infestations. It is prescription-only and considered safe and well-tolerated when used appropriately

. Ivermectin has been widely studied and is on the World Health Organization's List of Essential Medicines. However, despite some misinformation, major health authorities such as the FDA, CDC, EMA, and WHO do not recommend ivermectin for the treatment or prevention of COVID-19, as there is no credible scientific evidence supporting its efficacy for this use

. In summary, ivermectin is a broad-spectrum antiparasitic drug used primarily to treat parasitic worm infections and certain external parasites in humans, with a well-established safety and efficacy profile for these indications