SAMSCA TABLET 15MG [SIN15934P]

Product Info

SAMSCA TABLET 15MG

[SIN15934P]

[INDICATIONS]

1. Hyponatremia

   The treatment of clinically significant hypervolemic and euvolemic hyponatremia [serum sodium < 125 mEq/L or hyponatremia that is symptomatic and has resisted correction with fluid restriction], including patients with heart failure, and Syndrome of Inappropriate Antidiuretic Hormone (SIADH).

2. Adjunct Treatment of Volume Overload in Heart Failure

   Volume overload in heart failure when adequate response is not obtained with other diuretics (e.g., loop diuretics).

   Limitations of Use:
   When conditions or symptoms due to volume overload are resolved, administration of SAMSCA should be discontinued. The efficacy and safety of SAMSCA for maintenance treatment following resolution have not been established. In a clinical study, 15 mg tolvaptan has been associated with worse clinical outcomes vs placebo when rated at 6 months (last visit).

[DOSAGE & ADMINISTRATION]

1. Usual Dosage in Adults

   Patients should be in a hospital for initiation and re-initiation of therapy to evaluate the therapeutic response and because too rapid correction of hyponatremia can cause osmotic demyelination resulting in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma and death.

   During initiation and titration, frequently monitor for change in serum electrolytes and volume.

   In order to avoid nocturnal urination, SAMSCA is recommended to be administered in the morning and swallowed whole with water regardless of meal. Fluid restriction during the first 24 hours of therapy with SAMSCA should generally be avoided. Patients receiving SAMSCA should continue ingestion of fluid in response to thirst.

   1. Hyponatremia

      The usual starting dose for SAMSCA is 15 mg administered once daily in adult. Increase the dose to 30 mg once daily, after at least 24 hours, to a maximum of 60 mg once daily, as needed to achieve the desired level of serum sodium. Do not administer SAMSCA for more than 30 days to minimize the risk of liver injury.

   2. Adjunct treatment of volume overload in heart failure

      SAMSCA should be used in combination with other diuretics, such as loop diuretics, thiazides, and aldosterone antagonists, since SAMSCA increases aquaresis but not natriuresis. There is no clinical experience of co-administration of SAMSCA with human atrial natriuretic peptide (hANP).

      The usual adult dose is 15 mg once daily but it is recommended to start from 7.5 mg/day for patients whose serum sodium is less than 125 mEq/L, patients in whom rapid plasma volume decrease is undesirable, elderly patients or patients with serum sodium concentration higher than 140 mEq/L.

      The starting dose of 7.5mg/day is recommended based on safety considerations. If clinical symptoms such as persistent thirst and dehydration are observed, dosage of SAMSCA should be reduced and appropriate measures such as fluid replenishment, including fluid therapy, should be taken in accordance with the symptoms. If there is no improvement in symptoms, SAMSCA should be discontinued.

      Administration of SAMSCA should not be continued after body weight has returned to the target level (body weight at which volume overload is appropriately controlled) or when conditions or symptoms due to volume overload are resolved.

      Administration of SAMSCA should not be continued if volume overload or body fluid retention is not improved.

2. Drug Withdrawal

   Following discontinuation from SAMSCA, patients should be advised to resume fluid restriction and should be monitored for changes in serum sodium and volume status.

3. Co-Administration with CYP 3A Inhibitors, CYP 3A Inducers and P-gp Inhibitors

   CYP 3A Inhibitors

   SAMSCA is metabolized by CYP 3A, and use with strong CYP 3A inhibitors causes a marked (5-fold) increase in exposure. The effect of moderate CYP 3A inhibitors on SAMSCA exposure has not been assessed. Avoid co-administration of SAMSCA and moderate CYP 3A inhibitors.

   CYP 3A Inducers

   Co-administration of SAMSCA with potent CYP 3A inducers (e.g., rifampin) reduces SAMSCA plasma concentrations by 85%. Therefore, the expected clinical effects of SAMSCA may not be observed at the recommended dose. Patient response should be monitored and the dose adjusted accordingly.

   P-gp Inhibitors

   SAMSCA is a substrate of P-gp. Co-administration of SAMSCA with inhibitors of P-gp (e.g., cyclosporine) may necessitate a decrease in SAMSCA dose.

2. Contraindications

1. Patients with known or suspected hypersensitivity (e.g. anaphylactic shock, rash generalized) to SAMSCA, benzazepine or benzazepine derivatives or to any ingredient of the drug.

2. Patients requiring urgent intervention to raise serum sodium acutely.

   SAMSCA has not been studied in a setting of urgent need to raise serum sodium acutely.

3. Inability of the patient to sense or appropriately respond to thirst.

   Patients who are unable to auto-regulate fluid balance are at substantially increased risk of incurring an overly rapid correction of serum sodium, hypernatremia and hypovolemia.

4. Hypovolemic hyponatremia

   Risks associated with worsening hypovolemia, including complications such as hypotension and renal failure, outweigh possible benefits.

5. Anuric patients

   In patients unable to make urine, no clinical benefit can be expected.

6. Volume depletion patients

7. Hypernatremia patients

8. Concomitant use of strong CYP3A inhibitors

   Ketoconazole 200 mg administered with SAMSCA increased SAMSCA exposure by 5-fold. Larger doses would be expected to produce larger increases in SAMSCA exposure. There is no adequate experience to define the dose adjustment that would be needed to allow safe use of SAMSCA with strong CYP 3A inhibitors such as clarithromycin, ketoconazole, itraconazole, ritonavir, indinavir, nelfinavir, saquinavir, nefazodone, and telithromycin.

9. SAMSCA contains lactose as an excipient. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take SAMSCA.

10. Use in Patients with Autosomal Dominant Polycystic Kidney Disease

    Samsca can cause serious and potentially fatal liver injury. SAMSCA should not be prescribed or used outside of the approved indications.

11. Use during pregnancy