Use of Tolvaptan in Hyponatremic Patients Reduces Hospital Costs, Study Finds

Tolvaptan, a vasopression V2 receptor antagonist used to increase low levels of sodium in the blood, could be a cost effective way of managing patients who have hyponatremia associated with the syndrome of inappropriate antidiuretic hormone secretion (SIADH), according to a study published in the journal Hospital Practice in February.

The study used data from the Study of Ascending Levels of Tolvaptan in Hyponatremia 1 and 2 (SALT-1 and SALT-2) trials to determine the reduction in cost associated with using tolvaptan compared to a placebo. The authors of the study used the Healthcare Cost and Utilization Project 2009 Nationwide Inpatient Sample database to estimate hospital cost and length of stay (LOS) for hospitalization of adult patients (age ≥ 18 years) with the SIADH.

The study showed that in the SALT-1 and SALT-2 trials, patients who received tolvaptan had a shorter hospital LOS (4.98 days) than those who received a placebo (6.19 days) based on data from 21,717 hospitalizations of patients with the SIADH. The mean hospital LOS for all patients was 5.7 days with a mean total hospital cost of $8667. When patients were treated with an inpatient tolvaptan treatment duration of 4 days at a wholesale acquisition cost of $250 per day, the result was an estimated 1.11 day reduction in hospital LOS among patients. When the cost of the drug was factored in, the estimated mean hospital cost reduction was $694 per admission in the United States.

“The estimated cost savings projected by the cost-offset model suggest a clinical and economic benefit of tolvaptan usage in the treatment of patients with the SIADH,” the authors wrote. “These findings can be useful for hospital pharmacy and therapeutics committees as they evaluate new drugs for formulary status.”

Tolvaptan was approved by the FDA in May 2009. It increases sodium in the blood by increasing the amount of water released from the body as urine. It is sold under the brand name Samsca.