Bupropion as a modulator of drug activity

Abstract

Dosage forms, drug delivery systems, and methods related to sustained release of dextromethorphan or improved therapeutic effects are disclosed. Typically, bupropion or a related compound is orally administered to a human being to be treated with, or being treated with, dextromethorphan.

What is claimed is: 
     
         1 . A method of treating depression, comprising: orally administering about 0.3 mg/kg to about 1 mg/kg of a dextromethorphan and about 90 mg to about 140 mg of a bupropion, twice a day for at least 23 days, to a human being suffering from depression. 
     
     
         2 . The method of  claim 1 , wherein about 0.6 mg/kg to about 0.8 mg/kg of the dextromethorphan is orally administered twice a day. 
     
     
         3 . The method of  claim 1 , wherein about 0.75 mg/kg of the dextromethorphan is orally administered twice a day. 
     
     
         4 . The method of  claim 1 , wherein about 100 mg to about 120 mg of the bupropion is orally administered twice a day. 
     
     
         5 . The method of  claim 1 , wherein about 105 mg of the bupropion is orally administered twice a day. 
     
     
         6 . The method of  claim 1 , wherein the dextromethorphan and the bupropion are orally administered for at least 35 days. 
     
     
         7 . The method of  claim 1 , wherein the human being is suffering from treatment-resistant depression. 
     
     
         8 . The method of  claim 1 , wherein the combination of the dextromethorphan and the bupropion is more effective than independently orally administering the same amount of the dextromethorphan or the bupropion alone. 
     
     
         9 . The method of  claim 1 , wherein the dextromethorphan is orally administered in a dosage form that provides immediate release of the dextromethorphan. 
     
     
         10 . The method of  claim 3 , wherein the dextromethorphan is orally administered in a dosage form that provides immediate release of the dextromethorphan. 
     
     
         11 . The method of  claim 1 , wherein the bupropion is orally administered in a dosage form that provides sustained release of the bupropion. 
     
     
         12 . The method of  claim 5 , wherein the bupropion is orally administered in a dosage form that provides sustained release of the bupropion. 
     
     
         13 . The method of  claim 10 , wherein about 105 mg of the bupropion is orally administered twice a day in a dosage form that provides sustained release of the bupropion. 
     
     
         14 . The method of  claim 13 , wherein the bupropion and the dextromethorphan are orally administered together in a single dosage form that is orally administered twice a day. 
     
     
         15 . The method of  claim 14 , wherein the dextromethorphan and the bupropion are orally administered for at least 5 weeks. 
     
     
         16 . The method of  claim 1 , wherein the bupropion comprises an enantiomeric excess of an enantiomer. 
     
     
         17 . The method of  claim 15 , wherein the bupropion comprises an enantiomeric excess of an R-enantiomer. 
     
     
         18 . The method of  claim 15 , wherein the bupropion comprises an enantiomeric excess of an S-enantiomer. 
     
     
         19 . The method of  claim 1 , wherein the dextromethorphan comprises a deuterium-modified dextromethorphan. 
     
     
         20 . The method of  claim 1 , wherein the human being is currently suffering from depression and has previously been unsuccessfully treated with at least two antidepressants. 
     
     
         21 . A method of treating treatment-resistant depression comprising:
 selecting a human being suffering from depression who has previously been unsuccessfully treated with at least one antidepressant; and   orally administering a dextromethorphan-bupropion combination treatment twice a day to the human being for at least about five weeks;   wherein the dextromethorphan-bupropion combination treatment comprises about 40 mg to about 70 mg of a dextromethorphan and about 100 mg to about 150 mg of a bupropion.   
     
     
         22 . The method of  claim 21 , wherein the bupropion comprises an enantiomeric excess of an enantiomer. 
     
     
         23 . The method of  claim 21 , wherein the dextromethorphan comprises a deuterium-modified dextromethorphan. 
     
     
         24 . The method of  claim 21 , wherein the dextromethorphan-bupropion combination treatment comprises about 40 mg to about 50 mg of the dextromethorphan. 
     
     
         25 . The method of  claim 21 , wherein the dextromethorphan-bupropion combination treatment comprises about 100 mg to about 110 mg of the bupropion. 
     
     
         26 . The method of  claim 21 , wherein the dextromethorphan-bupropion combination treatment comprises about 100 mg to about 110 mg of the bupropion. 
     
     
         27 . The method of  claim 26 , wherein the dextromethorphan and the bupropion are orally administered in a single dosage form that is immediate release for the dextromethorphan and sustained release for the bupropion. 
     
     
         28 . The method of  claim 27 , further comprising orally administering the dextromethorphan-bupropion combination treatment once a day for about 1, 2, 3, 4, 5, 6, or 7 days prior to orally administering the dextromethorphan-bupropion combination treatment twice a day to the human being for at least about five weeks. 
     
     
         29 . The method of  claim 28 , wherein the dextromethorphan-bupropion combination treatment comprises about 45 mg of the dextromethorphan. 
     
     
         30 . The method of  claim 29 , wherein the dextromethorphan-bupropion combination treatment comprises about 105 mg of the bupropion.