If u r on methadon 90mg an u get high off of heroine? i'm not asking because i'm an addict i'm concerned about someone else

Not a good idea: Methadone and heroin can be lethal if combined. Dying from a big opiate dose can do the following: cardiopulmonary edema is a condition that causes fluid to pool around the lungs and heart, so the person can drown in their own fluids because oxygen can't get to the body. Also, aspiration and bacterial pneumonia could be another cause of death. Take your friend to the er.