The purpose of the present invention is to discover a pharmaceutical preparation which is for treating or preventing glaucoma or intraocular hypertension and exhibits effects on a patient in which the efficacy of a therapeutic agent for glaucoma or intraocular hypertension is insufficient. It is found that omidenepag, an ester thereof, or a salt thereof is proven to exhibit an excellent intraocular tension depressive action on a patient in which the efficacies of other therapeutic agents for glaucoma or intraocular hypertension are insufficient. Therefore, omidenepag, an ester thereof, or a salt thereof according to the present invention is useful as a pharmaceutical preparation capable of treating or preventing glaucoma or intraocular hypertension even on a patient in which the efficacies of other therapeutic agents for glaucoma or intraocular hypertension are insufficient.