PROBLEM TO BE SOLVED: To provide a vascular permeability inhibitor with few side effects and high safety which medically treats eye diseases associated with edema and bleeding such as diabetic macular edema, exudative age-related macular degeneration, and myopic macular degeneration, and lung diseases associated with edema and bleeding such as acute lung injury and acute respiratory distress syndrome, and which can alleviate patients physical pain and patients QOL.SOLUTION: The invention provides a vascular permeability inhibitor containing nitrate which inhibits vascular permeability and is used for the prevention or treatment of diseases associated with at least one of edema and bleeding caused by vascular permeability enhancement. The vascular permeability inhibitor of the invention is preferred to be administered within a range of 5-1300 &mumol/kg per day in terms of nitrate ion. The vascular permeability inhibitor of the invention is also preferred to be administered frequently to inhibit fluctuation of the nitrate ion concentration in plasma.
