FITCHBURG — A 37-year-old Gardner man has agreed to plead guilty to swapping hospice and dementia patients' oxycodone with allergy and thyroid pills at a Fitchburg healthcare facility — and then taking the diverted opioids himself — federal prosecutors announced Monday.

Beginning in or around September 2024 and continuing through February 2025, Milgrim allegedly diverted oxycodone from patients in the skilled nursing and dementia care units of an unnamed Fitchburg healthcare facility, according to court filings. He started by pocketing 5-milligram oxycodone pills that had been prescribed on an "as needed" basis — pills he allegedly consumed himself instead of giving them to the patients they were meant for.

To cover the theft, prosecutors say, Milgrim replaced the missing oxycodone with Loratadine — a common over-the-counter allergy medication whose appearance closely resembles a 5-mg oxycodone pill. Dying and cognitively impaired patients who needed pain relief instead received antihistamines.

In or around January 2025, according to the filings, Milgrim escalated. He allegedly diverted 10-mg oxycodone pills prescribed to an elderly patient held in the facility's locked dementia unit and swapped them out with Levothyroxine, a thyroid hormone medication. Patients in locked memory-care units are among the least able to advocate for themselves or verify what they are being handed.

The announcement was made by U.S. Attorney Leah B. Foley; Roberto Coviello, Special Agent in Charge of the U.S. Department of Health and Human Services Office of Inspector General; Michael Ahearn, Acting Special Agent in Charge of HHS-OIG; and Massachusetts Department of Public Health Commissioner Robert H. Goldstein. Assistant U.S. Attorney Kaitlin Brown is prosecuting the case.

Milgrim is presumed innocent unless and until proven guilty beyond a reasonable doubt.