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 a stimulating agent for preventing or treating glaucoma.
