An avalanche of misinformation about the antiparasitic drug ivermectin’s ability to treat COVID-19 has caused a series of national problems, from increased calls to poisoning centers to a shortage of the medicine itself. Patients have become desperate for a treatment that’s most commonly used for livestock and have taken their disputes over ivermectin with hospitals to court. Disinformation has flooded the internet, where dozens of Facebook groups centered around ivermectin remain active despite insufficient evidence that the medicine works in treating people for COVID-19. It’s also gone well beyond the internet to popular podcast hosts like Joe Rogan, who has...