Bupropion is the generic (common or non-branded) name for bupropion hydrochloride, the active ingredient in the branded drug, Zyban. It was originally marketed as an antidepressant drug under the brand name of Wellbutrin, but approved by the Food and Drug Administration (FDA) as a quit-smoking aid in 1997, after it became obvious that Bupropion was an effective quit aid, because smokers using it to treat depression also lost interest in smoking.
It isn't completely understood how Bupropion works, but it’s known that the drug alters brain chemistry in such a way that nicotine is made less effective. The result is a reduced interest in smoking, and nicotine cravings and withdrawal are minimal.
While this medication was developed as an anti-depressant, you do not need to suffer from depression for it to work as a quit aid. That said, if you develop quit-related depression, Bupropion may help to offset the symptoms.
In 2009, the FDA required the makers of Zyban and Chantix, a similar quit aid to post a warning on product packaging about potentially severe side effects.
Bupropion has many side effects, ranging from the common, those you should seek immediate medical attention for, to those that warrant stopping the drug immediately.
If any of the above side effects become severe or don't go away, see your doctor.
If you experience any of these side effects, discontinue Bupropion and see your doctor or go to an emergency room right away.
If you have any problems not listed here that are troublesome and you're concerned about whether they might be related to Bupropion, check in with your doctor as soon as possible.