The present invention provides a triazolopyridine compound having a prolyl hydroxylase inhibitory action and an erythropoietin production-inducing ability. The present invention relates to a compound represented by the following formula [I]:wherein each symbol is as defined in the specification, or a pharmaceutically acceptable salt thereof, or a solvate thereof, as well as a prolyl hydroxylase inhibitor or erythropoietin production-inducing agent containing the compound. The compound of the present invention shows a prolyl hydroxylase inhibitory action and an erythropoietin production-inducing ability and is useful as a prophylactic or therapeutic agent for various diseases and pathologies (disorders) caused by decreased production of erythropoietin.本發明提供具有脯胺醯基羥化酶抑制作用及紅血球生成素生產誘導能力之三唑并吡啶化合物。本發明係關於下式[I]所示之化合物、或其醫藥上可接受之鹽、或其溶劑合物：其中，各符號係如說明書中所定義；以及含有該化合物之脯胺醯基羥化酶抑制劑或紅血球生成素生產誘導劑。本發明之化合物具有脯胺醯基羥化酶抑制作用及紅血球生成素生產誘導能力，且係適用為因紅血球生成素之生產減少所導致之多種疾病及病變(疾患)的預防劑或治療劑。
