Cornerstone drug for low salt rejected by US panel WASHINGTON (Reuters) - Cornerstone Therapeutics Inc failed to win a U.S. advisory panel's support on Thursday for a drug that treats low sodium levels in the blood. The panel of outside advisers to the Food and Drug Administration voted five to three to recommend rejection of lixivaptan for treating low sodium due to a condition that causes the body to have excess water. They also unanimously voted against using the drug to treat low sodium in heart failure patients. The FDA usually follows panel recommendations, but it is not required to. A final decision is expected by October 29. Shares of the company were halted pending the panel meeting. Most panel members said the drug's risks outweighed its modest benefit in raising sodium levels, and called for more trials to make sure it was safe. In a clinical trial in heart failure patients, lixivaptan was linked to more deaths compared to placebo -- though it was uncertain whether the drug actually caused the deaths. Panel member Dr. Vasilios Papademetriou, a cardiologist at the Veterans Affairs Medical Center in Washington, D.C., said he wants to treat his patients with drugs that either improve their symptoms or help them live longer. "This drug in these studies has shown neither," he said at the meeting, monitored via a webcast. So I don't think that there is enough for me to consider this medication as essential or necessary in the market. Low sodium levels in the blood, known as hyponatremia, is the most common electrolyte disorder among Americans, affecting up to six million people. It is often tied to congestive heart failure. Although most people with the condition have no symptoms, in severe cases it can cause swelling of the brain, respiratory arrest and death. Cornerstone had been seeking to use the drug in two conditions that can cause low sodium levels: congestive heart failure and syndrome of inappropriate antidiuretic hormone secretion (SIADH), which causes the body to develop excess water and is caused by improper chemical signals. Reporting by Anna Yukhananov; Editing by Gerald E. McCormick and Tim Dobbyn