Samsca

Tolvaptan

Clinically significant hypervolemic & euvolemic hyponatremia (serum Na <125 mEq/L or symptomatic hyponatremia that has resisted correction w/ fluid restriction) including patients w/ heart failure & syndrome of inappropriate antidiuretic hormone (SIADH). Adjunct treatment of vol overload in heart failure.

Adult Hyponatremia Initially 15 mg once daily. May be increased to 30 mg once daily, after at least 24 hr. Max dose: 60 mg once daily, as needed. Max duration of treatment: 30 days. Adjunct treatment of vol overload in heart failure 15 mg once daily. Elderly, patient w/ serum Na <125 mEq/L, undesirable rapid plasma vol decrease or serum Na conc >140 mEq/L Initially 7.5 mg daily.

May be taken with or without food: Avoid grapefruit juice.

Hypersensitivity to tolvaptan, benzazepine or its derivatives. Patients requiring urgent intervention to acutely raise serum Na; who are unable to auto-regulate fluid balance. Hypovolemic hyponatremia. Anuria. Vol depletion. Hypernatremia. Concomitant use w/ strong CYP3A inhibitors (eg, clarithromycin, ketoconazole, itraconazole, ritonavir, indinavir, nelfinavir, saquinavir, nefazodone & telithromycin). Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption. Autosomal dominant polycystic kidney disease. Pregnancy.

Initiate & re-initiate only in a hospital where serum Na can be closely monitored. Frequently monitor serum Na & vol status after administration. Risk of osmotic demyelination syndrome. Interrupt or discontinue treatment & administer hypotonic fluid if too rapid increase in serum Na develops (ie, >12 mEq/L in 24 hr or 18 mEq/L in 48 hr). Assess serum Na conc & neurologic status during initiation & after titration. Risk for too rapid serum Na correction in patients w/ SIADH or w/ very low baseline serum Na conc. Avoid fluid restriction during the 1st 24 hr of therapy. Co-administration w/ diuretics; other treatment for hyponatremia & serum Na conc-increasing medications. Limit duration of therapy to 30 days. Dehydration can occur; monitor fluid & electrolyte status. Interrupt or discontinue therapy if medically significant hypovolemia signs & symptoms develop. Exclude pseudohyponatremia in DM patients w/ an elevated glucose conc (eg, >300 mg/dL) prior & during treatment. May cause hyperglycemia; cautiously manage patients w/ inadequately controlled type II DM. Rapid vol decrease or hemoconcentration associated w/ rapid diuresis may induce hypernatremia; thromboembolism in patients w/ serious CAD or cerebrovascular disease & elderly patients. Monitor serum K levels after treatment initiation in patients w/ hyperkalemia or in those receiving serum K-increasing drugs. Increased risk of developing acute retention in patients w/ partial obstruction of urinary outflow (eg, patients w/ prostatic hypertrophy or micturition impairment). Not recommended to be used concomitantly w/ hypertonic saline. Co-administration w/ CYP3A inhibitors & inducers (eg, rifampin, rifabutin, rifapentin, barbiturates, phenytoin, carbamazepine, St. John's Wort); P-gp inhibitors (eg, cyclosporine). When used as an adjunct treatment of vol overload in heart failure, measure serum Na conc at least 4-6 hr & 8-12 hr after administration on the 1st day; measure everyday from 2nd to 7th day; measure at appropriate intervals if continued further. May occasionally cause dizziness, asthenia or syncope when driving vehicles or using machines. Risk of serious & potentially fatal liver injury. Avoid use in patients w/ underlying liver disease, including cirrhosis. Promptly perform liver function tests in patients reporting symptoms indicating liver injury; promptly discontinue use if liver injury is suspected. Renal impairment. Women of childbearing potential should use effective contraception during treatment. Lactation. Childn & adolescents <18 yr. Elderly.

Thirst, dry mouth, asthenia, constipation, pollakiuria/polyuria & hyperglycemia. Increased blood creatinine, blood urea & blood uric acid. Diarrhea; malaise; increased blood glucose & K, decreased BP, presence of blood urine; dizziness, headache.

Increased exposure w/ ketoconazole & other strong CYP3A inhibitors (eg, clarithromycin, itraconazole, telithromycin, saquinavir, nelfinavir, ritonavir & nefazodone); grapefruit juice. Avoid co-administration w/ moderate CYP3A inhibitors. Reduce dose of Samsca in patients concomitantly treated w/ P-gp inhibitors (eg, cyclosporine). Reduced exposure w/ rifampin & other CYP3A inducers (eg, rifabutin, rifapentin, barbiturates, phenytoin, carbamazepine & St. John's Wort). Not recommended to concomitantly use w/ serum Na conc-increasing medications. Increased digoxin conc. Risk of hyperkalemia w/ angiotensin receptor blockers, ACE inhibitors & K sparing diuretics. May interfere w/ V₂ agonist activity of desmopressin. Not recommended to concomitantly use w/ hypertonic saline.

Diuretics

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

POM