Steward Cross
Concise Prescribing Info
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 inapproptiate antidiuretic hormone (SIADH).
Dosage/Direction for Use
Adult 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.
May be taken with or without food: Avoid grapefruit juice.
Patients w/ known or suspected 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.
Special Precautions
Initiate & re-initiate only in a hospital where serum Na can be monitored closely. Frequently monitor serum Na & vol status after administration. Risk of osmotic demyelination. Interrupt or discontinue treatment, & administer hypotonic fluid if too rapid increase in serum Na develops (ie, >12 mEq/L/24 hr). Assess serum Na conc & neurologic status during initiation & post-titration. Risk for too rapid serum Na correction on patients w/ SIADH or w/ very low baseline serum Na conc. Fluid restriction during the 1st 24 hr of therapy should generally be avoided. 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 thromboembolism in patients w/ serious CAD or cerebrovascular disease & elderly patients. Monitor serum K levels after initiation in patients w/ hyperkalemia or who are 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). May occasionally cause dizziness, asthenia or syncope when driving vehicles or using machines. Risk of serious & potentially fatal liver injury. Patients w/ underlying liver disease (including cirrhosis). Perform liver function tests promptly in patients reporting symptoms indicating liver injury; promptly discontinue if liver injury is suspected. Patients w/ renal impairment; not recommended in patients w/ CrCl <10 mL/min. Women of childbearing potential should use effective contraception during treatment. Lactation. Childn & adolescents <18 yr. Elderly.
Adverse Reactions
Thirst, dry mouth, asthenia, constipation, pollakiuria/polyuria & hyperglycemia.
Drug Interactions
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). Concomitant use w/ serum Na conc-increasing medications is not recommended. Increased digoxin conc. Risk of hyperkalemia w/ angiotensin receptor blockers, ACE inhibitors & K-sparing diuretics. May interfere w/ V2-agonist activity of desmopressin. Concomitant use w/ hypertonic saline is not recommended.
MIMS Class
ATC Classification
C03XA01 - tolvaptan ; Belongs to the class of vasopressin antagonists. Used as diuretics.
Samsca tab 15 mg
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