LITTLE ROCK, Ark (AP) — A northwest Arkansas jail and its doctor are asking a federal judge to dismiss a lawsuit by inmates who say they were unknowingly given ivermectin to treat COVID-19, despite health officials’ warnings that the drug shouldn’t be used for that purpose.

Attorneys for the Washington County sheriff, the county jail and Dr. Robert Karas cited several grounds in a court filing Monday for why they believe the lawsuit filed last month should be dismissed

The four-page document says there’s no constitutional violation because “physicians are permitted to exercise medical judgment in the treatment of inmates.”

Sheriff Tim Helder in August revealed that Karas had prescribed ivermectin to treat some inmates with COVID-19.

The Food and Drug Administration has approved ivermectin for use by people and animals for some parasitic worms, head lice and skin conditions. The FDA has not approved its use in treating or preventing COVID-19 in humans. According to the FDA, side effects for the drug include skin rash, nausea and vomiting.

The inmates said they were never told ivermectin was among the medications they had been given to treat COVID-19, and instead were told they were being given vitamins, antibiotics or steroids.

Karas was originally scheduled to appear this week before the state Medical Board, which was investigating complaints about the drug’s use at the jail. But the panel has rescheduled that hearing to April due to winter storms expected to hit the region this week.