Conivaptan for hyponatremia in the neurocritical care unit.

INTRODUCTION: Conivaptan is the first arginine vasopressin antagonist to be FDA-approved for the treatment of euvolemic hyponatremia, a common complication in neurointensive care patients. Due to risks for cerebral edema and seizures, sodium levels are generally aggressively maintained within normal levels (135-145 meq/l) in this patient population.
OBJECTIVE: To assess the safety and efficacy of conivaptan for the treatment of euvolemic hyponatremia in the neurocritical care unit.
METHODS: Data were obtained retrospectively on 22 patients treated with conivaptan for euvolemic hyponatremia. End points evaluated included time to [Na] increase of >or=6 meq/l; incidences of rapid overcorrection of [Na] (defined as an increase of >12 meq/l in a 24-h period while on conivaptan), infusion site reactions, or other adverse events; and whether sodium levels decreased after discontinuation of conivaptan.
RESULTS: A [Na] increase of >or=6 meq/l was reached in 19/22 (86%) patients, with an average time to goal of 13.1 h. No patients experienced a rapid overcorrection of [Na]. Five patients had an infusion site reaction necessitating an IV change. One patient experienced hypotension and another complained of thirst during infusion. Conivaptan was initiated in 11/22 patients (50%) who were hyponatremic despite already being on conventional therapies.
CONCLUSION: Conivaptan was safe and effective in this small series of neurointensive care patients, including many patients who were hyponatremic despite traditional treatments to maintain normal sodium levels. Further studies are needed to clarify the role of conivaptan as an adjunctive and/or alternative therapy for hyponatremia in this patient population.