check out this website
http://www.helpguide.org/mental/bipolar_disorder_medications.htm
I'm on Symbyax for my bipolar. I don't know if its covered by medicare. But its basically Zyprexa and Prozac in one pill. It helps me out.
Some of the one I am familiar with are Abilify, Geodon, Depakote, Lamictal, Lithium, Remeron, Aoloft, Prozac, and many many more. You may want to post and ask for a website link to get more info. I know one site www. NAMI.org is very good and has links. I think it boils down to good old fashion research.
Usually it's a combination of 2 or 3 meds to treat the different symtoms of Bipolar. Most people are not on just one med. They usually take a moog stabelizer along with an antidepressant and quite often one other medication depending on the type of Bipolar you ahve. I would Google "Medications used to treat Bipolar Disorder" you may come up with a whole laundry list. I think that's how I found my medications. Ther are also some brand new ones out but I'm sure they are pricey. I don't think Seroquel alone is enough to treat most people with bipolar. I hope you get some answers, I know you are desperate for them. Good Luck,
Erin