SAMSCA® (tolvaptan) is the first-and-only oral vasopressin
V2-receptor antagonist that increases serum sodium concentration through free water clearance
- Proven effective for clinically significant hypervolemic and euvolemic hyponatremia
- Represents an important treatment option for clinically significant dilutional hyponatremia1,2
- In healthy subjects, after a single 60-mg dose of SAMSCA, free water clearance and serum sodium increase occurred within 2 to 4 hours post-dose
Targeted MOA: Vasopressin
1. SAMSCA blocks vasopressin SAMSCA selectively blocks the binding of vasopressin to the V2-receptors in the renal collecting ducts.2-4
Increases free water clearance
2. Decreased expression of aquaporin Inhibition of vasopressin binding to the V2-receptor leads to decreased expression and removal of aquaporin-2 from the luminal membrane.3,5
3. Decreased water reabsorption V2-receptor blockade results in decreased water reabsorption by the kidney.3-5
Onset of aquaretic effect
4. Diuresis vs aquaresis Diuresis and aquaresis are different. Diuresis is an increase in overall urine production. SAMSCA provides aquaresis, or excretion water without clinically significant electrolyte loss.6
5. Serum sodium concentration and urine osmolality Aquaresis results in increased serum sodium concentration and decreased urine osmolality.
6. Sodium and potassium excretion This process does not, however, result in significant change in urinary excretion of sodium or potassium, nor does it result in increased plasma potassium.