A compound of the formula (I): R1—NH—X—Y-Z (I) wherein each symbol is as defined in the specification, or a pharmaceutically acceptable salt thereof useful as a vascular adhesion protein-1 (VAP-1) inhibitor, a pharmaceutical composition, a method for preventing or treating a VAP-1 associated disease, especially macular edema, which method includes administering an effective amount of the compound or a pharmaceutically acceptable salt thereof to a mammal, and the like.