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 increasing dextromethorphan plasma levels, comprising co-administering bupropion and dextromethorphan once a day or twice a day for at least 8 consecutive days to a human being who is a non-poor metabolizer of dextromethorphan; wherein about 50 mg to about 220 mg of the bupropion is co-administered with the dextromethorphan once a day or twice a day; and wherein co-administering the bupropion and the dextromethorphan results in an C avg  of dextromethorphan on the eighth day that is about 20 times to about 1,000 times the C avg  of dextromethorphan that would result from administering the same amount of the dextromethorphan without the bupropion for eight consecutive days; and wherein the bupropion and the dextromethorphan are co-administered to the human being for the treatment of agitation associated with Alzheimer’s disease. 
     
     
         2 . The method of  claim 1 , wherein co-administering the bupropion and the dextromethorphan results in an C avg  of dextromethorphan on the eighth day that is about 20 times to about 60 times the C avg  of dextromethorphan that would result from administering the same amount of the dextromethorphan without the bupropion for eight consecutive days. 
     
     
         3 . The method of  claim 2 , wherein about 70 mg to about 150 mg of bupropion hydrochloride, or a molar equivalent amount of the free base form or another salt form of bupropion, is co-administered with about 40 mg to about 60 mg of dextromethorphan hydrobromide, or a molar equivalent amount of the free base form or another salt form of dextromethorphan, once a day or twice a day. 
     
     
         4 . The method of  claim 3 , wherein the C avg  of dextromethorphan on the eighth day is about 90 ng/mL. 
     
     
         5 . The method of  claim 3 , wherein the C avg  of dextromethorphan on the eighth day is about 65 ng/mL to about 141 ng/mL. 
     
     
         6 . The method of  claim 5 , wherein about 105 mg of bupropion hydrochloride, or a molar equivalent amount of the free base form or another salt form of bupropion, is co-administered with about 44 mg to about 46 mg of dextromethorphan hydrobromide, or a molar equivalent amount of the free base form or another salt form of dextromethorphan, once a day or twice a day. 
     
     
         7 . The method of  claim 3 , wherein the C avg  of dextromethorphan on the eighth day is at least about 65 ng/mL. 
     
     
         8 . The method of  claim 2 , wherein the C avg  of dextromethorphan on the eighth day is about 65 ng/mL to about 141 ng/mL. 
     
     
         9 . The method of  claim 1 , wherein the dextromethorphan is formulated for immediate release, and the bupropion is formulated for sustained release. 
     
     
         10 . The method of  claim 1 , wherein the dextromethorphan and the bupropion are the only therapeutically active agents administered to the human being. 
     
     
         11 . The method of  claim 1 , wherein the dextromethorphan and the bupropion are in a single dosage form. 
     
     
         12 . The method of  claim 1 , wherein the bupropion and the dextromethorphan are co-administered once a day or twice a day for at least 14 consecutive days. 
     
     
         13 . The method of  claim 1 , wherein the bupropion and the dextromethorphan are co-administered once a day or twice a day for at least 30 consecutive days. 
     
     
         14 . The method of  claim 1 , wherein the human being is converted to poor metabolizer of dextromethorphan on the eighth day after co-administering the bupropion and the dextromethorphan. 
     
     
         15 . The method of  claim 3 , wherein the dextromethorphan is formulated for immediate release and the bupropion is formulated for sustained release. 
     
     
         16 . The method of  claim 3 , wherein the dextromethorphan and the bupropion are the only therapeutically active agents administered to the human being. 
     
     
         17 . The method of  claim 3 , wherein the dextromethorphan and the bupropion are in a single dosage form. 
     
     
         18 . The method of  claim 3 , wherein the bupropion and the dextromethorphan are co-administered once a day or twice a day for at least 14 consecutive days. 
     
     
         19 . The method of  claim 3 , wherein the bupropion and the dextromethorphan are co-administered once a day or twice a day for at least 30 consecutive days. 
     
     
         20 . The method of  claim 3 , wherein the human being is converted to poor metabolizer of dextromethorphan on the eighth day after co-administering the bupropion and the dextromethorphan.