Metolazone is a widely used diuretic medication that is used to treat a variety of conditions. However, like all medications, metolazone may contain impurities that can affect its effectiveness and safety. These impurities can include residual solvents, starting materials, and other impurities that may be introduced during the manufacturing process. It is important to closely monitor these impurities to ensure that metolazone is safe and effective for patients.