Pharmaceutical compositions containing as an active ingredient compounds of the general formula (I), prodrugs of the same, pharmaceutically acceptable salts of both, or solvates of them and exhibiting thrombopoietin receptor agonism: X1—Y1-Z1-W1  (I) wherein X1 is optionally substituted aryl, optionally substituted heteroaryl or the like; Y1 is —NRACO—(CH2)0-2— or the like (wherein RA is a hydrogen or the like); Z1 is optionally substituted phenylene or the like; and W1 is a group represeted by the below formula: wherein R1, R2, R3, and R4 are each independently a hydrogen atom, optionally substituted lower alkyl or the like, a broken line ( - - - ) represents the presence or absence of bond.