Vaprisol is a medicine given in a vein to raise low blood sodium levels in hospitalized patients with ?euvolemic hyponatremia.? Euvolemic hyponatremia is when a patient has too little sodium in the bloodstream but a normal amount of fluid present in the body.

Vaprisol, made by Astellas Pharma US, Incorporation is used for the treatment of euvolemic hyponatremia. The approval was based on data from a randomized, double-blind study in 56 patients with mild to moderate euvolemic hyponatremia, showing that use of 40 mg/day of Vaprisol for 4 days corrected hyponatremia in 66.7% of patients compared with 28.6% of those receiving placebo. Vaprisol yielded significant improvements in serum sodium concentration within 1 day of initiation, with 52% of patients achieving an increase of 4 mEq/L or greater.

Adverse events most commonly associated with Vaprisol use included infusion site reactions, hypokalemia, headache, thirst, and vomiting. Most reactions were mild in severity and did not resulted in discontinuation of therapy. Rotation of the injection site for every 24 hours is recommended.

Vaprisol therapy is initiated with a 20-mg intravenous loading dose, followed by 20 mg administered as a continuous infusion for 24 hours. Following the initial day of treatment, Vaprisol may be given for an additional 1 to 3 days as a continuous infusion of 20 mg/day.

For patients who develop hypovolemia or hypotension during treatment, Vaprisol should be discontinued and volume status/vital signs frequently monitored. Treatment may be resumed at a lesser dose if hyponatremia persists once the patient is euvolemic and normotensive.

Vaprisol should be used with caution in patients with hepatic or renal impairment because of the potential for increased systemic exposure.