A former executive of Insys Therapeutics has been criminally charged for leading a special “reimbursement unit” at the company that defrauded insurers into paying for a potent opioid pain medication by falsely claiming patients had cancer and other conditions needed for pre-approval. Elizabeth Gurrieri, a former manager of reimbursement services for Arizona-based Insys, was charged with wire fraud conspiracy in a criminal complaint filed in federal court in Boston. The complaint sheds light on a Connecticut case involving a Derby nurse who has been charged with taking kickbacks from Insys in exchange for prescribing the company’s fentanyl spray, Subsys. The nurse, Heather Alfonso, has been cooperating with investigators in Boston and Connecticut in an ongoing probe of Insys’ sales tactics. The complaint against Gurrieri notes that patients needed prior authorizations from insurance companies to cover the costs of Subsys, an expensive drug approved by the Food and Drug Administration in 2012 for the management of breakthrough pain in patients with cancer who already were receiving opioid pain treatment.