An object of the present invention is to find a novel pharmaceutical that has an excellent tryptophanase inhibitory effect, and suppresses worsening of renal function to preserve the kidney by reducing production of indoxyl sulfate in the blood. Provided is a pharmaceutical composition containing, as an active ingredient, a compound represented by formula (I) or a pharmacologically acceptable salt thereof. In the formula (I), R
1
and R
2
are the same or different, and represent a C
1
-C
6
alkyl group, a halogeno C
1
-C
6
alkyl group or a C
3
-C
6
cycloalkyl group; n represents 0, 1 or 2; each X represents a C
1
-C
6
alkyl group, a C
3
-C
6
cycloalkyl group, a halogen atom or the like; and Y represents a hydrogen atom, a C
1
-C
6
alkoxy group, a C
3
-C
6
cycloalkoxy group or a halogeno C
1
-C
6
alkoxy group.
本发明的一个目的是寻找一种具有优异
色氨酸酶抑制作用的新型药物,并通过减少血液中
吲哚硫酸盐的产生来抑制肾功能恶化,以保护肾脏。提供的是一种含有以下化合物或其药理学可接受的盐作为活性成分的药物组合物。在式(I)中,R1和R2相同或不同,表示C1-C6烷基、卤代C1-C6烷基或C3-C6环烷基;n表示0、1或2;每个X表示C1-C6烷基、C3-C6环烷基、卤素原子或类似物;Y表示氢原子、C1-C6烷氧基、C3-C6环烷氧基或卤代C1-C6烷氧基。