Major opioid maker Purdue Pharma is arguing that an Ohio lawsuit should be thrown out because the Food and Drug Administration approved the use of its popular painkiller.

Ohio is among several states suing opioid makers, and says the companies falsely marketed the drugs and downplayed the addictive effects of opioid painkillers that drove an epidemic still ravaging the United States. Purdue Pharma, maker of popular painkiller Oxycontin, argues that it marketed the drugs according to FDA guidelines.

The lawsuit, and others filed from several states and localities, are a response to a nationwide epidemic that took 33,000 lives in 2015, according to federal data.

Ohio argued in its lawsuit that Purdue Pharma marketed the drugs to treat chronic pain. Ohio defines chronic pain as noncancer pain lasting three or more months. However, Purdue Pharma says that the FDA approved Purdue's long-acting products to treat chronic pain that includes noncancer pain.

Purdue also said the lawsuit is pre-empted by federal law and prior decisions made by the FDA.

For instance, in 2013 the advocacy group Physicians for Responsible Opioid Prescribing issued a petition asking the FDA to strip the chronic pain indication from opioids' label. The FDA declined to strip the indication or add any warning that there isn't enough evidence to show that the benefits outweigh the risks of long-term use in treating non-cancer pain.

Purdue argues that any statements that the painkillers shouldn't be used for noncancer pain would go against FDA labeling and conflict with its obligations under federal law.

Purdue also faces lawsuits from Oklahoma, Missouri, Mississippi, New Hampshire and South Carolina. Several counties in New York and California, as well as the city of Chicago, have sued opioid makers, too.

The attorney for the eight New York counties that sued Purdue Pharma blasted the defense.

"We find Purdue's motion to be interesting but fatally flawed," said attorney Paul Hanly in a statement to the Washington Examiner. "Interesting because the argument that FDA regulation of opioids means there can be no lawsuits has been around for decades, yet just months ago, in nearly identical litigation filed against it by Suffolk County, New York, Purdue submitted hundreds of pages of legal argument to the Court but omitted this argument. Why? There can be but one answer: Purdue knew the argument has no sound basis in the law. To assert it in the Ohio case is a desperate but doomed attempt to confuse the pertinent issues."