• Monitor neurologic status and assess for signs and symptoms of osmotic demyelination syndrome (trouble speaking, dysphagia, drowsiness, confusion, mood changes, involuntary movements, weakness, seizures), especially during initiation and after titration. If a rapid ↑ in sodium or symptoms occur, discontinue tolvaptan and consider administration of hypotonic fluid.
• Monitor fluid balance. If hypovolemia occurs interrupt or discontinue tolvaptan and provide supportive care (monitor vital signs, balance fluid and electrolytes).
• Monitor for signs and symptoms of liver injury (fatigue, anorexia, right upper abdominal discomfort, dark urine, jaundice) periodically during therapy. If symptoms occur, discontinue therapy.

Lab Test Considerations:

• Monitor serum sodium levels frequently during initiation and dose titration and periodically during therapy. Too rapid correction of hyponatremia (>12 mEq/L/24 hr) can cause osmotic demyelination syndrome.
  • Monitor serum potassium in patients with serum potassium >5 mEq/L or taking medication known to ↑ potassium.
  • Monitor ALT, AST, and bilirubin 2 wk and 4 wk after starting therapy, then monthly for first 18 mo and every 3 mo thereafter. If ALT, AST, or bilirubin increase to >2 × upper limit of normal (ULN), immediately discontinue Jynarque; repeat tests as soon as possible (within 48–72 hr). If levels stabilize or resolve, Jynarque may be reinitiated with increased frequency of monitoring as long as ALT and AST remain below 3 times ULN. Do not restart in patients with signs or symptoms of hepatic injury or whose ALT or AST ever exceeds 3 x ULN during therapy with tolvaptan, unless another explanation for liver injury exists and the injury has resolved. In patients with a stable, low baseline AST or ALT, an increase >2 x baseline, even if <2 x ULN, may indicate early liver injury. Suspend and promptly (48–72 hr) reevaluate liver enzymes before reinitiating therapy with more frequent monitoring.