$ENDP March 14 (Reuters) - South Dakota on Wednesday sued three major drugmakers, accusing them of deceptively marketing prescription opioids and contributing to a nationwide epidemic.

Marty Jackley, the state's attorney general, announced civil claims against Purdue Pharma LP, a unit of Endo International Plc and Johnson & Johnson's Janssen unit.

The lawsuit makes South Dakota at least the 16th U.S. state to sue manufacturers over opioids, which can be used to treat pain.

Jackley said the drugmakers have violated Medicaid fraud laws and state deceptive trade laws, and created a public nuisance by spreading false information about opioids' risks and benefits.

He said their conduct has fueled abuse of opioids in South Dakota, where nearly 596,000 prescriptions for a total of 39.3 million doses were filled in 2017.

South Dakota's population is about 870,000.

"Pharmaceutical companies that knowingly and deceptively harm consumers must be held accountable," Jackley said in a statement.

Purdue and Janssen said in separate statements they were committed to finding ways to curb opioid abuse, and rejected the respective allegations against them. Endo declined to comment.

Opioids, including prescription painkillers and heroin, played a role in a record 42,249 U.S. deaths in 2016, up 47 percent from 2014, according to the U.S. Centers for Disease Control and Prevention. (Reporting by Jonathan Stempel in New York Editing by Tom Brown)