Methods for the treatment of itching comprising administering PGD2 receptor antagonists

Abstract

A PGD 2 receptor antagonist such as a compound of the formula (IA-a-5): a pharmaceutical acceptable salt thereof or a hydrate thereof, has an efficacious activity for the prevention or treatment of itching and is useful as a medicament.

1 . A pharmaceutical composition for the prevention or treatment of itching which comprises a PGD 2  receptor antagonist.  
     
     
         2 . A pharmaceutical composition for the prevention or treatment of itching which comprises a compound of the formula (I):  
       
         
           
           
               
               
           
         
       
       wherein  
       
         
           
           
               
               
           
         
       
       R is hydrogen, alkyl, alkoxy, halogen, hydroxy, acyloxy or optionally substituted arylsulfonyloxy, X is hydrogen or alkyl and the double bond on the α chain has E configuration or Z configuration, a pharmaceutically acceptable salt thereof or a hydrate thereof.  
     
     
         3 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IA):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutically acceptable salt thereof or a hydrate thereof.  
     
     
         4 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IB):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         5 . A pharmaceutical composition for the prevention or treatment of itch according to  claim 2  which comprises a compound of the formula (IA-a):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         6 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IA-b):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         7 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IA-c):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         8 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IA-d):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         9 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IA-b′):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         10 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IB-a′):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         11 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IB-b′):  
       
         
           
           
               
               
           
         
       
       wherein R and X are as defined above and the double bond on the α chain has E configuration or Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         12 . A pharmaceutical composition for the prevention or treatment of itching according to any one of claims  2 - 11  which comprises the compound wherein the double bond on the α chain has E configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         13 . A pharmaceutical composition for the prevention or treatment of itching according to any one of claims  2 - 11  which comprises the compound wherein the double bond on the a chain has Z configuration, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         14 . A pharmaceutical composition for the prevention or treatment of itching according to any one of claims  2 - 13  which comprises the compound wherein R is hydrogen, methyl, methoxy, bromo, fluoro, hydroxy, acetoxy or phenylsulfonyloxy and X is hydrogen, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         15 . A pharmaceutical composition for the prevention or treatment of itching according to any one of claims  2 - 13  which comprises the compound wherein R is hydroxy and X is hydrogen, a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         16 . A pharmaceutical composition for the prevention or treatment of itching according to  claim 2  which comprises a compound of the formula (IA-a-5):  
       
         
           
           
               
               
           
         
       
       a pharmaceutical acceptable salt thereof or a hydrate thereof.  
     
     
         17 . A pharmaceutical composition according to any one of claims  1 - 16  for the prevention or treatment of itching wherein the itching is caused by an antigen.  
     
     
         18 . A pharmaceutical composition according to any one of claims  1 - 16  for the prevention or treatment of itching wherein the itching is derived from atopic dermatitis.  
     
     
         19 . A pharmaceutical composition according to any one of claims  1 - 16  for the prevention or treatment of itching wherein the itching is derived from urticaria.  
     
     
         20 . A pharmaceutical composition according to any one of claims  1 - 16  for the prevention or treatment of itching wherein the itching is derived from allergic conjunctivitis.  
     
     
         21 . A pharmaceutical composition according to any one of claims  1 - 16  for the prevention or treatment of itching wherein the itching is derived from allergic rhinitis.  
     
     
         22 . A pharmaceutical composition according to any one of claims  1 - 16  for the prevention or treatment of itching wherein the itching is derived from contact dermatitis.