(The anti parasite drug for livestock was promoted on Fox News as a Covid-19 treatment)

(CNN)The Arkansas Medical Board is investigating after a doctor said he prescribed an anti-parasitic drug "thousands" of times for treatment of Covid-19, including to inmates in an Arkansas jail.

The FDA has been warning against the use of ivermectin for treatment of Covid-19 since March. The drug is used to treat parasitic infections, primarily in livestock, and the CDC recently cautioned about an increase in reports to poison centers of severe illness caused by the drug.