1 week ago i started zyban (bupropion) to quit smoking and i went up 300mg and i have started to itch all over. no hives or spots just goes red from itching help?

Stop smoking: You are probably sensitive or allergic to zyban (bupropion). Stop it immediately and see if your itching goes a way within a few weeks.

Stop Zyban (bupropion): Any drug can cause a reaction and thus stopping zyban (bupropion) for a week or two may answer your question. I do applaud you for trying to quite smoking- don't be discouraged since there are other options.