Researchers analyzing insurance claims data estimate that U.S. insurers have paid tens of millions of dollars for ivermectin as a covid-19 treatment, despite little good evidence that ivermectin does anything to treat or prevent the viral illness. During a single week in August 2021, private and Medicare insurance plans forked over about $2.5 million for covid-related prescriptions of ivermectin, according to the new study, published Thursday in JAMA. Ivermectin is a cheap and effective antiparasitic that’s been in wide use for around 40 years. At the start of the pandemic, it was one of many existing drugs to receive a...