A newer-generation anti-depressant, bupropion SR is in a class by itself and has no appreciable effect on the brain chemical serotonin, as do the majority of newer anti-depressants. Bupropion SR works by increasing available amounts of norepinephrine and dopamine, two other brain chemicals implicated in the reward and pleasure pathways.
Gadde says its unique mechanism of action may account for why patients remark that bupropion does not suppress their appetite, but rather helps them feel satisfied more easily. "A lot of patients have said that, while on the drug, they can eat a small piece of pie and feel satisfied, although not necessarily full. So it appears they feel rewarded much quicker than they normally do without the drug." The only side effect commonly reported in this study was dry mouth. Burpopion SR is not approved by the FDA for weight loss and should not be used by patients with seizure disorders, anorexia or bulimia, Gadde said.
The study will continue for another 18 months. Data also are being collected on bone density and lean muscle mass. Preliminary results should be available later this summer.