Samsca

Clinically significant hypervolemic & euvolemic hyponatremia, including patients w/ heart failure & SIADH.

Adult Initially 15 mg once daily, increased to 30 mg once daily after at least 24 hr to a max of 60 mg once daily as needed to achieve desired level of serum Na. Do not administer for >30 days to minimize risk of liver injury.

May be taken with or without food.

Hypersensitivity. Use in patients w/ autosomal dominant polycystic kidney disease (ADPKD) outside of FDA-approved risk evaluation & mitigation strategy (REMS). Setting of urgent need to raise serum Na acutely. Patients w/ inability to sense or appropriately respond to thirst. Hypovolemic hyponatremia. Concomitant use w/ strong CYP3A inhibitors. Anuric patients.

Risk of osmotic demyelination syndrome w/ too rapid correction of hyponatremia (eg, >12 mEq/L/24 hr); slower rates of correction may be advisable in susceptible patients, including those w/ severe malnutrition, alcoholism or advanced liver disease. Monitor serum Na conc & neurologic status, especially during initiation & after titration. Discontinue or interrupt treatment & consider administration of hypotonic fluid in patients who develop too rapid a rise in serum Na. Avoid fluid restriction during the 1st 24 hr of therapy. Can cause serious & potentially fatal liver injury. Avoid use in patients w/ underlying liver disease, including cirrhosis. Dehydration & hypovolemia can occur, especially in potentially vol-depleted patients receiving diuretics or those who are fluid-restricted. Patients should continue ingestion of fluid in response to thirst. Associated w/ acute reduction of extracellular fluid vol which could result in increased serum K. Monitor serum K levels after initiation of treatment in patients w/ serum K >5 mEq/L & those who are receiving drugs known to increase serum K levels. Concomitant use w/ hypertonic saline is not recommended. Avoid concomitant use w/ moderate CYP3A inhibitors. Avoid co-administration w/ CYP3A inducers. Dose reduction when co-administered w/ P-gp inhibitors. Not recommended in patients w/ CrCl <10 mL/min. Should be used during pregnancy only if potential benefit justifies potential risk to fetus. Discontinue nursing or discontinue Samsca. Safety & effectiveness in ped patients have not been established.

Thirst, dry mouth, asthenia, constipation, pollakiuria/polyuria, hyperglycemia.

Increased exposure w/ strong CYP3A inhibitors (eg, ketoconazole, clarithromycin, itraconazole, telithromycin, saquinavir, nelfinavir, ritonavir, nefazodone); moderate CYP3A inhibitors (eg, erythromycin, fluconazole, aprepitant, diltiazem, verapamil); grapefruit juice; P-gp inhibitors (eg, cyclosporine). Reduced exposure w/ CYP3A inducers (eg, rifampin, rifabutin, rifapentine, barbiturates, phenytoin, carbamazepine, St. John's wort). Increased AUC & C_max of digoxin. May interfere w/ V2-agonist activity of desmopressin.

Diuretics

C03XA01 - tolvaptan ; Belongs to the class of vasopressin antagonists. Used as diuretics.

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