| abstract |
The invention provides compounds of the formula (I) or a pharmaceutically acceptable salt thereof, wherein, R<1> is optionally substituted tetrazolyl, R<2> is optionally substituted phenyl, optionally substituted pyridinyl or optionally substituted thienyl, and R<3>, R<4>, R<5> and R<6> are as defined herein. Also provided are methods of using the compounds for treating diseases mediated by a P2X3 and/or a P2X2/3 receptor antagonist and methods of making the compounds. |