Serum sodium concentration
The effect of Vaprisol on serum sodium was demonstrated in a double-blind, placebo-controlled, randomized, multicenter study in patients with euvolemic or hypervolemic hyponatremia (serum sodium 115-130 mEq/L), the primary efficacy endpoint of which was change from baseline in serum sodium during the course of treatment, measured by the baseline-adjusted area under the sodium-time curve (AUC) from the beginning through the end of treatment. Fluid restricted to ≤2.0 L/day in all patients. The mean baseline serum sodium concentrations in patients treated with Vaprisol or placebo were 123.3 mEq/L or 124.3 mEq/L, respectively.1,2
In clinical studies of patients with hyponatremia (serum sodium <130 mEq/L), Vaprisol significantly increased the baseline-adjusted serum sodium area during a 4-day treatment period1
- A 6.5 mEq/L mean change from baseline in serum sodium concentration was achieved at the end of Vaprisol treatment (day 4) compared with 1.5 mEq/L for placebo
- 69% of patients receiving Vaprisol 40 mg/day IV achieved a ≥6 mEq/L increase in serum sodium concentration or normal serum sodium concentration by the end of treatment (day 4) compared with 21% of patients receiving placebo1*
- By day 2, 41% of patients receiving Vaprisol achieved a ≥6 mEq/L increase in serum sodium concentration or normal serum sodium concentration compared with 0% of patients receiving placebo1
- In controlled clinical trials, about 9% of patients who received Vaprisol in doses of 20-40 mg/day IV had rises of serum sodium >12 mEq/L/24 hours, but none of these patients had evidence of osmotic demyelination or permanent neurologic sequelae1
*The effect of Vaprisol on maintenance of serum sodium concentration is not known.