Tolvaptan interactions

Food & lifestyle

• grapefruit juice

  Moderate

  Metabolism

  Grapefruit juice may significantly increase the plasma concentrations of tolvaptan. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits.

  What to do: Patients treated with tolvaptan should avoid consumption of grapefruits and grapefruit juice.

  1 source

  1. "Product Information. Samsca (tolvaptan)." Otsuka American Pharmaceuticals Inc (2009):

Conditions

Conditions in which Tolvaptan needs care, as documented in this source.

• Kidney Diseases

  Major

  There are no clinical trials of tolvaptan in patients with CrCl < 10 mL/min, and because drug effects on serum sodium levels are likely lost at very low levels of renal function, use in these patients is not recommended. Additionally, no benefit can be expected in anuric patients, so the use of tolvaptan is contraindicated in these patients.

  1 source

  1. "Product Information. Samsca (tolvaptan)." Otsuka American Pharmaceuticals Inc (2009):

• Liver Failure

  Major

  Tolvaptan can cause serious and potentially fatal liver injury. Patients with symptoms that indicate liver injury such as fatigue, anorexia, right upper abdominal pain, dark urine or jaundice should discontinue treatment right away. Therapy duration should be limited to 30 days. The use of tolvaptan should be avoided in patients with underlying liver disease, including cirrhosis, because the ability to recover from liver injury may be impaired.

  1 source

  1. "Product Information. Samsca (tolvaptan)." Otsuka American Pharmaceuticals Inc (2009):

• Liver Diseases

  Moderate

  Osmotic demyelination syndrome is a risk associated with overly rapid correction of hyponatremia (> 12 mEq/L/24 hours). This syndrome can result in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizure, coma or death. Patients with advanced liver disease, alcoholism or severe malnutrition are at increased risk and require slower rates of correction. Serum sodium concentration and neurological status should be monitored appropriately during treatment administration. Vasopressin antagonists should be initiated and re- initiated in patients only in hospital settings were sodium levels can be monitored closely.

  2 sources

  1. "Product Information. Vaprisol (conivaptan)." Cumberland Pharmaceuticals Inc (2006):
  2. "Product Information. Samsca (tolvaptan)." Otsuka American Pharmaceuticals Inc (2009):