The American College of Medical Toxicology’s Toxicology Investigators Consortium (ToxIC) has received several reports of patients who became ill from using ivermectin formulations to prevent or treat COVID-19 infection. These incidents were reported through ToxIC’s FDA ACMT COVID-19 ToxIC (FACT) Pharmacovigilance Project Sub-registry between October 2020 and August 2021.
Ivermectin is FDA-approved for prescription use in humans as an antiparasitic drug to treat conditions including intestinal strongyloidiasis and onchocerciasis or river blindness. A topical form is used for the treatment of head lice and rosacea. Veterinary formulations are also used to treat animals including cattle and horses. Cases reported to ToxIC’s FACT project included the use of human and veterinary formulations and have resulted in some cases in severe toxicity and morbidity.
There is currently no recommendation or approved indication to use ivermectin to treat or prevent COVID-19. The National Institute of Health COVID-19 Treatment Center States, “There is insufficient evidence for the COVID-19 Treatment Guidelines Panel (the Panel) to recommend either for or against the use of ivermectin for the treatment of COVID-19. Results from adequately powered, well-designed and well-conducted clinical trials are needed to provide more specific, evidence-based guidance on the role of ivermectin in the treatment of COVID-19.”
Although ivermectin is relatively well tolerated when used as prescribed, toxicity can occur in the setting of overdose or inappropriate use, especially when veterinary formulations are involved. Clinical manifestations range in severity and body organs involved. They include gastrointestinal effects (e.g., nausea, vomiting, abdominal pain and diarrhea), headache, dizziness, fatigue, visual changes or problems, fast heart rate, low blood pressure and skin rashes. More severe central nervous effects have been reported and include coma, altered mental status, seizures, hallucinations and tremors.