Compounds of general formula (I) wherein R1, R2, R3, R4, R5 and X are as defined herein are inhibitors of the epithelial sodium channel (ENaC) and are useful for the treatment or prevention respiratory diseases and conditions, skin conditions and ocular conditions.一種通式(I)化合物 其中R1、R2、R3、R4、R5與X係如本文中定義,其為上皮鈉離子通道(ENaC)之抑制劑,適用於治療或預防呼吸疾病與病症、皮膚病症與眼睛病症。