The Justice Department last week joined the case against Insys Therapeutics, which has been accused of peddling kickbacks to doctors to encourage them to prescribe the powerful opioid Subsys.  

Insys founder John Kapoor has maintained his innocence in the face of charges, though two other Insys employees have pleaded guilty to their involvement in the alleged kickback scheme. The civil case is part of a probe into the company’s marketing for Subsys, its spray form of fentanyl, the powerful synthetic opioid.
Criminal cases against several practitioners and former company execs, including sales reps and Kapoor himself, are also pending.
The government’s involvement in the case came as a new study appeared in the journal JAMA Internal Medicine, finding that doctors who received free meals and other services from pharmaceutical companies were more likely to prescribe opioid painkillers to their patients. 
The researchers found that 369,139 physicians prescribed an opioid painkiller at least 10 times in 2015 under Part D plans. After consulting the Centers for Medicare & Medicaid Services’ Open Payments database, the report found that 7% of the same group received “opioid-related payments” from drug companies in 2014.
That link may not be easy to establish. For one, the study suggests a correlation, not necessarily causation. Moreover, most opioid deaths come not from prescriptions penned by doctors, but through mail orders from China and Mexico that make their way to vendors on the streets, observed Dr. Giovanni Ciavarra, a senior consultant with the consulting firm Innovative Science Solutions. Recent research has also suggested that people metabolize opioids differently, and that some simply have a higher propensity for dependence.
“Most people who are given a seven-day prescription of opioids after a surgery [for instance], very few would develop a dependence, which would further lead to an addiction,” he said, adding that some individuals require higher doses for pain relief. The only way for a physician to know how his or her patient will metabolize opioids is to give a genetic test, Ciavarra explained. 
There are also significant legal hurdles the prosecution will have to overcome in its case against Insys, said George Talarico, an attorney who has worked with Ciavarra on presenting the defense perspective on other opioid cases. He said the case against Insys will depend on the ability to prove that the kickbacks were inextricably linked to the opioids prescribed. 
“You would have to prove that the bribes — they call them bribes — these gifts that they gave to doctors, [led] them [to] write a specific prescription to a person, and but for that influence they wouldn’t have done it,” he said. “That’s kind of a hard concept to get around.”