FAYETTEVILLE, Ark. (AP) — A federal judge has refused to dismiss a lawsuit that says detainees at an Arkansas jail were given the drug ivermectin to fight COVID-19 without their knowledge.

The lawsuit contends detainees at the Washington County Jail in Fayetteville were given ivermectin as early as November 2020 but were unaware until July 2021. Ivermectin is approved by the Food and Drug Administration to address parasitic infestations such as intestinal worms and head lice and some skin conditions, such as rosacea. It is not, and was not at the time, approved to treat COVID-19.

U.S. District Judge Timothy L. Brooks ruled Thursday that the lawsuit could move forward, saying Dr. Robert Karas used detainees for an experiment, The Northwest Arkansas Democrat-Gazette reported.

Plaintiffs in the case include Edrick Floreal-Wooten, Jeremiah Little, Julio Gonzales, Thomas Fritch and Dayman Blackburn. The case was filed by the American Civil Liberties Union last year against Karas, Karas Correctional Health, former Washington County Sheriff Tim Helder and the Washington County Detention Center.

In a written opinion, Brooks said that Karas began conducting his own research and hypothesized the drug could be an effective treatment for COVID-19.

Karas prescribed ivermectin to two groups of test subjects. The first was composed of people who sought out Karas’ services at his private medical clinic and agreed to take ivermectin as part of an experimental treatment for COVID-19, Brooks noted. The second set was composed of detainees who were incarcerated at the jail.

“The inmates received Dr. Karas’ treatment protocol for COVID-19, but did not know it included Ivermectin,” Brooks wrote. “Dr. Karas and his staff falsely told the inmates the treatment consisted of mere ‘vitamins,’ ‘antibiotics,’ and/or ‘steroids.’ Critically, the inmates had no idea they were part of Dr. Karas’ experiment.”

Since the detainees were never told that their “treatments” contained ivermectin, they were never warned about the drug’s side effects, Brooks said. According to the FDA, side effects for the drug include skin rash, nausea and vomiting.

In addition, Karas hypothesized that large doses of ivermectin would be most effective in combating COVID-19. The problem, however, was that the FDA had only approved a dosage of 0.2 mg/kg to treat worms, according to Brooks. Karas ultimately prescribed lower doses of ivermectin to his clinic patients and higher doses to his imprisoned patients.

“At first reading, it would seem highly unlikely — even implausible — that a doctor would have dosed his incarcerated patients with an experimental drug more aggressively than his private patients, but plaintiffs point to proof in their jail medical records,” Brooks wrote.

Brooks also said it was possible that Helder knew or should have known that Karas was performing ivermectin experiments on detainees without their knowledge because of Karas’ social media postings and that he approved, condoned or turned a blind eye to this violation of their rights.

“The incarcerated individuals had no idea they were part of a medical experiment,” Gary Sullivan, legal director of the ACLU of Arkansas, said in a news release Friday. “Sheriff Helder and Dr. Karas routinely mischaracterized the fundamental nature of plaintiffs’ claims in their request for dismissal by refusing to mention the most significant allegations in the complaint.”

Brooks found Karas is not entitled to the immunity that protects states and local governments against damages from damages unless they violate the constitution. Brooks said Karas and his clinic had sought and won a county contract to provide health care to hundreds of detainees at the jail over many years at a cost of more than $1.3 million a year.

Brooks also said the detainees have stated a plausible claim for battery in that Karas intentionally concealed the details of a treatment in order to induce a captive audience to take a particular drug for his own professional and private aims.