Chemically, bupropion is unrelated to any other major antidepressant, and why it works is still not known. Initial dosage should be no more than 150 mg/day but this may be increased to no more than 300 mg/day on the fourth day when used as a stop-smoking aid, and eventually to 400 mg (sustained release) or 450 mg (immediate release) when used to treat depression. At doses of 400-450 mg/day the risk of seizure increase from 0.1% (at 300 mg/day) to 0.4%.
Patients who experience agitation, restlessness or insomnia should remain on a lower dose longer and/or increase the dosage more gradually. It may take 1-4 weeks for patients taking bupropion to feel the full benefits. Note: The seizure risk is more greatly increased above 450 mg/day.
Most common side effects include headache, dry mouth, nausea and insomnia. Bupropion is considered weight neutral, and while some patients reported weight gain, more report weight loss. A small percentage of patients experienced anorexia while taking bupropion. Patients with a history of anorexia nervosa or bulimia, or with a history of seizures, should not take this medication.
- Buproprion should not be taken at the same time as any MAOI antidepressant, and in addition, two weeks should pass before a patient stops taking one and starts taking the other.
- This medication is not known to be dangerous during pregnancy or nursing, but your obstetrician and pediatrician should know all medications you are taking at all times.
- If you miss a dose, SKIP IT. The risk of seizure is dose dependent, and doubling up is more likely to cause seizure.
- Never take both Wellbutrin AND Zyban. All you'd be doing is increasing the dosage to a possibly dangerous level.
- The use - especially excessive use - of alcohol increases the risk of seizure while taking bupropion.
- Care should be taken when combining Wellbutrin or Zyban with the anticonvulsant medications phenytoin (brand name Dilantin), carbamazepine (brand name Tegretol) (which is commonly used to treat bipolar disorder), or phenobarbital, or with the ulcer medication cimetidine (brand name Tagamet).
- Some sources recommend that Bupropion not be taken by anyone who cannot afford to lose more than 5% of current body weight.