@Juhstin Guessing Fentanyl. Personally knew a nursing home nurse, on graveyard shift, who would take fentanyl patches off sleeping residents and put them on herself. She was found, unconscious one night, almost covered in the partially used patches. Coma for a while, due to stroke from the overdose. She recovered, and even eventually was giving her license back by the state.
Easy to target resident care facilities, I reckon. Fewer employees to observe thefts.