abstract |
The present invention relates to a composition comprising a compound of formula (I) contained in a pharmaceutically acceptable carrier and to a method of preventing or treating pruritus using the composition, wherein in formula (I), M is a), (b) or (c), wherein R, R 2 , R 3 , R 4 , R 7 , Ar 1 and Ar 2 are as defined in the specification: |