Just the other day, my brand new pdoc started me on Lamictal, and mentioned reducing the Wellbutrin after a couple weeks. I asked if I could start reducing the Wellbutrin right away because the side effects are getting annoying at the max dose, and she agreed. I think it helped that I'm clearly not depressed right now!

Then when she started explaining what to expect with Lamictal and I mentioned "The Rash" she was really pleased that I had already looked into some of the common meds for bipolar. She said she really likes working with people who take ownership of their health and are willing to do some research on their own behalf.

So I wouldn't hesitate to ask - but do be careful about how you ask. Like others have said, keeping a respectful tone and couching your request in terms that shows that you've given it real consideration should help others understand your position.