Bupropion as a modulator of drug activity

A method of treating major depressive disorder, comprising administering a dosage form by mouth once daily for three days followed by twice daily by mouth to a human patient in need thereof for a total of at least 8 days, wherein the dosage form consists essentially of about 105 mg of bupropion hydrochloride and about 45 mg of a dextromethorphan salt, wherein the human patient does not experience an adverse event as a result of receiving the dosage form, wherein on the eighth day that the dosage form is administered, the Cmax of bupropion in the human patient is about 9×101 ng/mL, and wherein the adverse event is dizziness.

A method of treating major depressive disorder, comprising orally administering a dosage form once daily by mouth for three days followed by twice daily by mouth to a human patient in need thereof, for a total of at least 8 days wherein the therapeutically active compounds in the dosage form consist of (i) about 105 mg of bupropion hydrochloride and (ii) about 45 mg of a dextromethorphan salt, wherein the human patient does not experience an adverse event as a result of receiving the dosage form, wherein on the eighth day that the dosage form is administered, the Cmax of bupropion in the human patient is about 9×101 ng/mL, and wherein the adverse event is dizziness.