A group of healthcare providers and others on Thursday sued Louisiana in an effort to block a law that classified mifepristone and misoprostol, the drugs used in medication abortion, as controlled substances in the state.

"Controlled substances" refer to drugs or other substances that are tightly controlled by the government because they may be abused or cause addiction.

The lawsuit was filed in Baton Rouge, Louisiana, state court by plaintiffs including the New Orleans-based Birthmark Doula Collective, a doctor, a pharmacist, and women who said they were denied medically necessary treatment as a result of the law and others.

The law at issue was signed by Governor Jeff Landry in May. It designates the two drugs, which the U.S. Food and Drug Administration approved more than two decades ago, as safe and effective for terminating pregnancies, as Schedule IV drugs, typically pain-killers and mood-altering medications that merit greater oversight due to their potential for abuse or dependence.

While abortion is illegal in Louisiana, with a narrow exception for medical emergencies, both drugs have other uses. Mifepristone is used to treat a hormonal disorder known as Cushing syndrome, and misoprostol to manage miscarriage and treat postpartum hemorrhage.

One consequence of the state's classification is that misoprostol will no longer be immediately available to emergency physicians in delivery wards, according to the lawsuit, potentially endangering patients. It alleges that the law violates women's right to due process under the state constitution.

"Restricting immediate access to essential medications like misoprostol compromises our ability to provide urgent, lifesaving care, putting more lives at risk in a system already strained by severe health inequities," Birthmark said in a statement.

Landry's office did not immediately respond to a request for comment.

Mifepristone is at the center of another high-profile lawsuit brought in 2022 in Texas by anti-abortion groups seeking to undo the drug's FDA approval.

A trial judge ruled in their favor, but the Supreme Court ruled that they lack standing, keeping the drug on the market for now. A group of conservative states is pressing forward with its challenge to the drug's approval.