The hydrochloride salt of an aminoketone antidepressant. The molecular mechanism of the antidepressant effect of bupropion is unknown. This agent does not inhibit monoamine oxidase and, compared to classical tricyclic antidepressants, is a weak blocker of the neuronal uptake of serotonin and norepinephrine. Buproprion also weakly inhibits the neuronal re-uptake of dopamine. or A drug used to relieve pain by blocking signals at nerve endings. It is being studied in the relief of pain following surgery for cancer. It is a type of local anesthetic. Also called bupivacaine, Marcaine, and Sensorcaine.