The U.S. Food and Drug Administration has approved Samsca tablets (tolvaptan) to treat hyponatremia, an abnormally low concentration of sodium in the blood.
"With the approval of Samsca, physicians will have an additional tool to treat hyponatremia," said Norman Stockbridge, M.D., director of the Division of Cardiovascular and Renal Products in the FDA's Center for Drug Evaluation and Research.
Samsca is approved to treat hyponatremia associated with congestive heart failure, liver cirrhosis, and the syndrome of inappropriate antidiuretic hormone secretion.
When sodium levels drop in the fluid outside of cells throughout the body, water moves into cells to balance the sodium levels and causes the cells to swell. Swelling of the brain cells is thought to cause many of the symptoms of hyponatremia. Those symptoms may include fatigue, weakness, headache, nausea, confusion or decreased consciousness, and convulsions. Severe hyponatremia, which has not been studied with Samsca, can lead to coma and death.
Samsca helps raise sodium levels in the blood by removing extra body water in the urine. Patients using the drug in clinical trials had a greater degree of increase in sodium levels in the blood compared with patients taking a pill containing no active drug (placebo).