What Is the Treatment to Demerol Drug Addiction?

My roommate Kit is addicted to a drug called Demerol. I think it’s a pain killer that she uses to maximize the effects brought by other sedatives. Demerol makes her drowsy, lightheaded, lethargic and sweaty. Lately, she told me that she’s having trouble with her stomach too. Now that she’s finally experiencing its side effects, Kit asked me to look for a possible treatment. She told me that she wants to quit taking Demerol and that she wants to change. Please help us. Thank you.