COMPOUNDS AND COMBINATIONS THEREOF FOR TREATING NEUROLOGICAL AND PSYCHIATRIC CONDITIONS
Dosage forms, drug delivery systems, and methods related to sustained release of dextromethorphan or improved therapeutic effects are disclosed. Typically, an antidepressant, such as bupropion or a related compound is orally administered to a human being to be treated with, or being treated with, dextromethorphan.
1 . A method of treating depression comprising: orally administering a dosage form to a human being in need thereof for at least 8 consecutive days, wherein the dosage form comprises a dextromethorphan and a fluoxetine, wherein the human being receives a total daily dose of about 30 mg to about 150 mg of the dextromethorphan; wherein the dextromethorphan and the fluoxetine are the only therapeutically active agents in the dosage form; wherein the human being is an extensive metabolizer of dextromethorphan; wherein on day 8, the human being has a dextromethorphan/dextrorphan plasma ratio of 0.3 or greater three hours after the dosage form is administered.
2 . The method of claim 1 , wherein the dosage form comprises about 20 mg to about 50 mg of the fluoxetine.
3 . The method of claim 1 , wherein the depression is major depressive disorder.
4 . The method of claim 1 , wherein the depression is treatment resistant depression.
5 . The method of claim 1 , wherein the dosage form is orally administered for at least 14 consecutive days.
6 . The method of claim 1 , wherein the dosage form provides immediate release of the dextromethorphan.
7 . The method of claim 1 , wherein the dosage form contains about 20 mg to about 50 mg of the dextromethorphan.
8 . The method of claim 1 , wherein the dosage form contains about 30 mg to about 60 mg of the dextromethorphan.
9 . The method of claim 1 , wherein the dosage form contains about 40 mg to about 50 mg of the dextromethorphan.
10 . The method of claim 1 , wherein the dosage form contains about 50 mg to about 70 mg of the dextromethorphan.
11 . The method of claim 1 , wherein the dosage form contains about 70 mg to about 100 mg of the dextromethorphan.
12 . The method of claim 1 , wherein the dosage form contains about 45 mg of a dextromethorphan salt.
13 . The method of claim 1 , wherein the dextromethorphan comprises a deuterium-modified dextromethorphan.
14 . The method of claim 1 , wherein the dosage form is a capsule, a tablet, or a solution.
15 . The method of claim 1 , wherein a dextromethorphan plasma level is increased as compared to administering the same amount of dextromethorphan alone.
16 . The method of claim 1 , wherein the human being is converted to a poor metabolizer of dextromethorphan.
17 . The method of claim 1 , wherein the dosage form further comprises a pharmaceutically acceptable excipient.
18 . The method of claim 1 , wherein the elimination half-life of dextromethorphan increases upon administration of the dosage form.