The document from the North Carolina Office of the Chief Medical Examiner says 30-year-old Cheryl Lynn Suber of Garner, NC died of complications of combined oxycodone and diphenhydramine poisoning.
The report says "two syringes with pink watery material were discovered with her body and were reportedly not known to be directly associated with her medical therapy."
The report says the contents of the syringes were tested, and they were found to contain diphenhydramine.
Suber died at Duke October 5. According to search warrants obtained by ABC11 in October, she was at the hospital for treatment for Sickle Cell Anemia, but went into cardiac arrest just hours after being seen walking around the hospital in apparent good health.
The warrants say a nurse told investigators that Suber's boyfriend came out of her room and requested she check on her. The nurse went in and found no pulse.
The attending physician - Doctor Daniel Kaplan - was suspicious and requested a police investigation.
The warrants show detectives are treating the case as a possible homicide, and seized surveillance video of anyone entering or exiting her room, they also asked to look at her medical records.
The autopsy report says the medical examiner also received an empty bottle of oxycodone pills with the body.
No charges have been filed in the case.
Contacted Tuesday, Duke police would not say if they believe Suber's death was accident or a homicide. They said the investigation remained "active."