During January of this year I got scabies from an ex-girlfriend of mine and since then my life's been a living hell of itching and bleeding from scratching. I've treated myself twice for it but it came back both times, the second time around everyone in the house started itching so my mom went to the doctor and got medication to get rid of it and said that everyone in the house probably had it too and they needed to be treated as well. So my friend who lives with us is on disability and can get the medication for free so we ask him to go to the doctor to get some, he comes out of the office and says the doctor told him he didn't have it so he apparently never bothered to ask for the medication. My parents and my sister are willing to take the medication as am I so we can just get rid of the damn things for good, but my asshole friend refuses to take the medication as he is still in denial about even having it. He's had it before when he was a kid and claimed his doctor said that he could never actually get it a second time, but thats bullshit because it can infect you as many times as it fucking wants, also when he left the doctors office I saw him throw away a paper, which I believe to be the prescription for the scabies med which he was supposed to get which tells me hes lying about everything the doctor said to him, also hes itching in the very same spots everyone else is, which are places that scabies are naturally found like about the waist and thighs, he just claims its a rash. But since hes a fucking goodie two shoes, my parents believe his story about the visit to the doctors and the rash, and unless he decides to man up and tell the truth, and take the medication, I'm stuck with scabies because everyone in the house has to be treated if its to completely rid us of scabies. SO what do I do?

Buy enough of the fucking medication for everyone. Your friend may be an asshole but short of forcing him at gunpoint, you aren't getting the medicine out of him.