I had a buddy just pass away within the year of an H overdose. He lived with a good friend of mine from college. Its been almost a year since his death and it came out that prior to his death he was narcan'd 5 times. His roommate didnt even know he had been narcanned. He was able to basically OD 5 times and continue to go to work and what not without his roommate knowing.
Next point about the take the addict out of his environment. It my help some but in the case of my cousin he was able to find other shitheads like him in the Marines, San Diego, NC, Prison, Jail, any city he was in he fell into and found other people like him.