A licensed practical nurse was arrested and charged with taking morphine prescribed for a patient and giving the patient a muscle relaxant instead, authorities said.

Nina Perez, 31, of Berwick, Maine, was arrested for unlawfully possessing a controlled drug and abuse of a facility patient, according to the Attorney General's Office.

While working as a licensed practical nurse at the Edgewood Center in Portsmouth on May 19, Perez took a quantity of morphine that was prescribed for a patient and retained it for her own use. Perez then administered the prescription drug flexeril, a muscle relaxant, to the patient as a substitute for the morphine.

Perez will be arraigned at 8 a.m. Sept. 17 at the 10th Circuit, District Division-Portsmouth.

The matter was referred to the Office of the Attorney General from the Office of the Long-Term Care Ombudsman. The Medicaid Fraud Unit, which investigates and prosecutes allegations of residence abuse at healthcare facilities, investigated Perez's alleged crimes.