WINONA — A 58-year-old Goodview man has pleaded guilty to a manslaughter charge in the drug-related death of his son.

Thirty-four-year-old Jeffery Jon Schumacher died May 8, 2012. A coroner ruled his cause of death to be mixed drug toxicity, a combination of methadone and venlafaxine.

According to court documents, his father Jeffery Jon Schumacher Sr. gave the methadone to his son.

Methadone is a synthetic narcotic sometimes prescribed to recovering heroin addicts. Venlafaxine is a prescription antidepressant.

Schumacher also pleaded guilty to a single charge of the sale of methadone to a person younger than 18, a charge contained in a second indictment.

His sentencing is set for Aug. 19.