The kidneys help to regulate how much water and salts are conserved or passed from the body. People with chronic kidney disease may have high levels of certain salts in their blood and medicines such as sevelamer are used to lower them. Ciclosporin is an immune suppressing medicine used to prevent kidney transplant rejections. Diabetes insipidus is a medical condition, unrelated to diabetes (diabetes mellitus), that affects how well the kidneys remove water from the blood. The medicine desmopressin is a common treatment for it.