Compositions for the treatment of cns-related conditions

Abstract

The invention provides methods for treating CNS-related conditions with amantadine and donepezil, in which the amantadine is in an extended release form, wherein the extended release amantadine formulation provides a change in plasma concentration as a function of time (dC/dT) that is less than 40% of the dC/dT of the same quantity of an immediate release form of amantadine.

What is claimed is: 
     
         1 . A method of treating a patient with a neurological condition, comprising orally administering to a human subject in need thereof:
 (a) 22.5 mg to 30 mg memantine or a pharmaceutically acceptable salt thereof provided in a sustained release dosage form, wherein said sustained release memantine provides a change in mean plasma concentration of memantine as a function of time (dC/dT) that is: (1) less than about 50% of the dC/dT provided by the same quantity of an immediate release form of memantine, determined in a time period between 0-Tmax of the immediate release form of memantine; and (2) 2.1 ng/ml/hr or less, determined in a time period of 0 to 4 hours; wherein dC/dT is measured in a single-dose human PK study; and   (b) a therapeutically effective amount of immediate release donepezil.   
     
     
         2 . The method of  claim 1 , wherein the dC/dT of 2.1 ng/mL/hr or less is determined in a time period of 2 to 4 hours. 
     
     
         3 . The method of  claim 1 , wherein the neurological condition is selected from the group consisting of Alzheimer's disease, dementia, Parkinson's disease, and neuropathic pain. 
     
     
         4 . The method of  claim 3 , wherein the dC/dT of 2.1 ng/mL/hr or less is determined in a time period of 2 to 4 hours. 
     
     
         5 . The method of  claim 1 , wherein the sustained release oral dosage form comprises 25 mg to 30 mg memantine or a pharmaceutically acceptable salt thereof. 
     
     
         6 . The method of  claim 5 , wherein the dC/dT of 2.1 ng/mL/hr or less is determined in a time period of 2 to 4 hours. 
     
     
         7 . The method of  claim 6 , wherein the neurological condition is selected from the group consisting of Alzheimer's disease, dementia, Parkinson's disease, and neuropathic pain. 
     
     
         8 . The method of  claim 5 , wherein the neurological condition is selected from the group consisting of Alzheimer's disease, dementia, Parkinson's disease, and neuropathic pain. 
     
     
         9 . The method of  claim 1 , wherein the sustained release oral dosage form comprises 28 mg memantine or a pharmaceutically acceptable salt thereof. 
     
     
         10 . The method of  claim 9 , wherein the dC/dT of 2.1 ng/mL/hr or less is determined in a time period of 2 to 4 hours.