WICHITA, Kan. — A Kansas physician-legislator, who has acknowledged he’s under investigation by the state medical board after supporting the deworming drug ivermectin, is instructing doctors on COVID-19 treatment in a letter.

The Wichita Eagle reports Kansas Sen. Mark Steffen sent a letter on official Senate stationery to health care providers telling them that the way COVID-19 patients are treated has changed and that they will be shielded from Board of Healing Arts “interference.”

The Hutchinson Republican cites the recent Senate passage of a measure that specifically authorizes doctors to prescribe ivermectin and hydroxychloroquine, among other drugs, to treat COVID-19. But the proposal remains bogged down in negotiations with the House.

Susan Gile, acting director of the Board of Healing Arts, said the board has no response to his letter and hasn’t changed its complaint or investigative process.

Steffen, an anesthesiologist who has acknowledged prescribing ivermectin, has declined to confirm whether the board’s investigation of him involves those prescriptions. But has said it includes his public statements, which have been supportive of ivermectin and other unproven COVID-19 treatments.

The FDA has tried to debunk claims that animal-strength versions of ivermectin can help fight COVID-19.