摘要 |
Compounds of formula I or pharmaceutically acceptable salts thereof: Formula (I) wherein R<SUP>1</SUP>, R<SUP>2</SUP>, R<SUP>3 </SUP>and R<SUP>8 </SUP>are as defined in the specification as well as salts and pharmaceutical compositions including the compounds are prepared. They are useful in therapy, in particular in the management of pain.
|