Provided is a pharmacotherapy for preventing glaucoma or preventing or treating ocular hypertension which has potent and immediate intraocular pressure lowering action and exhibits prolonged duration of the action. A combination of (S)-(-)-1-(4-fluoro-5-isoquinolinesulfonyl)-2-methyl-1,4-homopiperazine, a salt thereof or a solvate thereof with an [alpha]2 stimulating agent for preventing or treating glaucoma.本發明提供一種眼壓下降作用強力並具有即效性且其持續時間經延長之用於預防青光眼或者預防或治療高眼壓症之藥物療法。本發明係一種用於預防或治療青光眼之(S)-(-)-1-(4-氟-5-異喹啉磺醯基)-2-甲基-1,4-高哌或者其鹽或其等之溶劑合物與α2興奮劑之組合。
