The US Department of Justice announced [press release] Tuesday that it joined [complaint, PDF] a whistleblower lawsuit against Insys Therapeutics Inc. on Monday in an effort to combat the opioid crisis.

The DOJ will take over prosecuting the False Claims Act case in the US District Court for the Central District of California [official website], against Insys, which produces the fentanyl nasal spray Subsys. According to the complaint, Insys has caused federal healthcare programs to pay for Subsys for uses which it is not covered. The DOJ explained Insys’s tactics, stating:

Since 2012, Insys has knowingly offered and paid kickbacks to induce physicians and nurse practitioners to prescribe Subsys for their patients. Many of these kickbacks have taken the form of speaker program payments for speeches to physicians that were, in fact, shams. Insys has also hired prescribers’ relatives and friends in order to induce prescriptions of Subsys. Insys has also provided prescribers with lavish meals and entertainment to induce them to prescribe Subsys.

The DOJ will also prosecute the case for violation of the Anti-Kickback Statute.

The DOJ has asked that the case be stayed [Reuters report] until the criminal charges against Insys founder John Kapoor are resolved.

The opioid crisis continues to flood courts across the US. In April, the state of Kentucky sued [complaint, PDF] several opioid manufacturers alleging that they “trivialized, mischaracterized, and failed to disclose” the “serious risk of addiction” inherent in the use of the high strength pain killers [JURIST report]. The Navajo Nation [official website] also filed a lawsuit [claim, PDF] in April in the US District Court for the District of New Mexico [official website] seeking damages from 11 major opioid drug manufacturers, distributors, and pharmacies.