Conivaptan and an initial study shows that it has some promise. Conivaptan is most commonly used in the hospital in cases of euvolemic and hypervolemic hyponatremia, conditions where the sodium level in the blood falls significantly below normal. In the United States hyponatremia affects about four percent of hospitalized patients. Although many patients do not show symptoms, extreme cases may result in brain swelling, respiratory arrest and even death. Hypervolemic hyponatremia specifically is when the body’s serum sodium levels fall below the total body water increase, which results in edema. This is associated with congestive heart failure, liver disease and kidney
Cerebral edema (ECF) in the brain is slightly lower than that of plasma. Plasma can be diluted by several mechanisms, including excessive water intake (or hyponatremia), syndrome of inappropriate antidiuretic hormone secretion (SIADH), hemodialysis, or rapid reduction of blood glucose in hyperosmolar hyperglycemic state (HHS), formerly known as hyperosmolar non-ketotic acidosis (HONK). Plasma dilution decreases serum osmolality, resulting in a higher osmolality in the brain compared to the serum. This creates an abnormal pressure gradient and movement of water into the brain, which can cause progressive cerebral edema, resulting in a spectrum of signs and symptoms from headache and ataxia to seizures