I began taking Effexor XR (300 mg) about six months ago, and at first it caused me to have an extremely dry mouth and a terrible taste in my mouth. Gum/mints/hard candy are extremely helpful, as is having plenty of water handy at all times. I don't know about the kidney thing, but your doctor's attitude about it would have made me angry, to say the least. What a jerk! Certainly, I would consult with someone else rather than risk harming your new kidney.

As a side note, I switched to regular Effexor when the generic version came on the market due to insurance issues, and it seems to have less side effects for me than the XR version. My doctor warned me that the side effects on the regular are usually really bad. Also, increasing my dosage to 400 mg he thought would really mess me up. I guess our bodies all react differenly.