NEW HAVEN — A former Connecticut nurse has avoided prison for her role in a scheme to prescribe a highly addictive fentanyl spray in exchange for kickbacks.

Federal prosecutors say 46-year-old Heather Alfonso was sentenced Tuesday to three years of probation and ordered to pay $2.5 million in restitution.

Prosecutors say as an advanced practice registered nurse at a Derby pain management clinic, Alfonso was allowed to prescribe medications. They say she often prescribed Subsys to patients when medically unnecessary. Subsys, a spray opioid, was approved to treat pain in cancer patients, yet many of her Medicare patients did not have cancer.

In exchange she received about $83,000 in kickbacks from the drugmaker, Insys Therapeutics Inc.

Alfonso said in court she was too easily tempted by “easy money” and made a “grave mistake.”