If your sister is an addict, the methadone is interacting as an addictive substance for her. It sounds as if it is causing her to avoid life, by sleeping
, or eating, watching tv, etc, which is what most addicts do. The methadone can do a world of good or a world of hurt. 90 mg is a relatively high dose, but within the recommended mg.
Methadone given for pain management usually works well, and this is what you can see when it is helping. If it is helping your sister sleep her life away, it is not a healthy medicine.
Is she using this as an attempt to avoid using other substances or is she using this for chronic pain? If it is being used to avoid other drugs, she is very addicted and will need to do something to assist her in stopping this usage.
The methadone clinics in town have counselors and group available to assist with this. If she is willing.
And that is the hardest part, if she is not willing, it will be an uphill battle, but it can be won.
I would suggest the family consult a professional interventionist, someone like Bradford, who can assist you in confronting her.
You will need all family and friends involved, including your parents who are supplying her with a place to live, food, etc. The goal here is to cut off all the things she is getting for free, which just enables her to continue this current lifestyle. It is a bit like tough love, but ya'll must be willing to follow through with whatever you threaten to do, if she does not get help.
You must be willing to go as far as to put her out in the street to live, until she decides to make alternate plans. This is truly a gesture of love. She is killing herself slowily with this drug.
She is wasting her life, and the disease of addictin has taken over.
I would also suggest you and your family attend some AL-Anon groups, to help you see what else can be done to help her get healthier, and to assist you with support.
Here is their website: www.al-anon.alateen.org/english.html
Please let me know if you have further questions. Gina