Attorneys representing reproductive health-care providers filed a lawsuit in state court Tuesday challenging Oklahoma’s most recent restrictions on nonsurgical abortions, arguing the law, which prohibits the off-label use of the drug RU-486 (or mifepristone), is unconstitutional.

Non-surgical or medication abortions typically involve the use of mifepristone, which is taken by the patient at her health-care facility, in conjunction with misoprostol, which is usually taken by the patient at home.

HB 2684, which was signed into law by Gov. Mary Fallin in April and is set to take effect November 1, requires physicians to ignore decades of medical research, the opinion of leading medical organizations, and their own clinical experience, and instead administer medication abortion drugs according to an outdated and inferior regimen, the complaint charges.

The law bans all medication abortions after 49 days of pregnancy, which advocates argue forces patients to undergo a surgical procedure when they otherwise would have the option of a safe abortion using medications alone.

HB 2684 is similar to a 2011 law that attempted to ban the off-label use of RU-486 or “any abortion-inducing drug.”

Reproductive rights advocates successfully challenged that law, which was permanently struck down last year by the Oklahoma Supreme Court. The court concluded that preventing doctors from using evidence-based medical procedures such as the off-label use of certain medications “is so completely at odds with the standard that governs the practice of medicine that it can serve no purpose other than to prevent women from obtaining abortions and to punish and discriminate against those who do.”

Attorneys for the State of Oklahoma petitioned the U.S. Supreme Court for a review of that ruling, but the Roberts Court declined, letting the ruling from the Oklahoma Supreme Court stand. Oklahoma lawmakers passed HB 2684 in response to that legal defeat.

“Oklahoma politicians are back at it again, playing doctor, intruding upon women’s private decisions, and pretending their actions are good for women’s health even though medical experts and associations nationwide make clear that they are absolutely not,” Nancy Northup, president and CEO of the Center for Reproductive Rights, said following the filing of the lawsuit.

“The true intent and effect of this law is to deny women an important option for ending a pregnancy safely and legally in the earliest stages,” she said. “That is plainly unconstitutional, and we are confident that the court, as it has so many times before, will stop it from ever going into effect.”

Major medical groups oppose laws like Oklahoma’s, which they say severely restrict access to medication abortion and improperly intrude on the doctor-patient relationship.

Both the American Medical Association (AMA) and the American College of Obstetricians and Gynecologist (ACOG) submitted amicus briefs opposing similar restrictions in Arizona and Texas, arguing that these restrictions ignore years of doctors’ practical experience and scientific advancement, forcing providers to prescribe the medication with an inferior, outdated, and less effective protocol.

Despite opposition from the medical community, federal and state courts have split on blocking restrictions like Oklahoma’s. Recently, the U.S. Court of Appeals for the Fifth Circuit upheld similar restrictions in Texas, while another federal court did the same for Ohio.

The Ninth Circuit Court of Appeals is considering a challenge to Arizona’s medication abortion restrictions while a state court in North Dakota blocked a similar law.