Preventive and / or therapeutic drug for polycystic kidney disease

The present invention provides a combined pharmaceutical of a sustained-release preparation for injection that is excellent in the prevention and / or treatment effect of multiple cystic kidneys. Specifically, a prophylactic and / or therapeutic agent for polycystic kidney, characterized by being a sustained-release preparation for injection containing particles containing tolvaptan or a prodrug thereof and a somatostatin analog, The present invention relates to a method for preventing and / or treating cystic kidney disease.