Kurt apparently had 3 times the lethal 225 mgs dose of heroin (1.52 mgs per liter) in his blood system and intravenous puncture marks in both arms. Medical experts will tell you that such an amount, when injected directly into the bloodstream will leave you incapacitated and cause you to lapse into a coma within seconds, if not kill you instantly before the needle can even be removed from your arm. It's common for deaths of heroin overdoses to be found with the needle still sticking out of the arm. That's how quickly one lethal dose can kill a person, let alone three.