Tolvaptan (tolvaptan) — Uses, Dosage, Side Effects & Safety

Drug class: Vasopressin V2-receptor antagonist (aquaretic)

Overview

Tolvaptan is a prescription medication used to treat low blood sodium levels (hyponatremia) caused by conditions such as heart failure and the syndrome of inappropriate antidiuretic hormone secretion (SIADH). It is also approved for slowing kidney function decline in adults with autosomal dominant polycystic kidney disease (ADPKD). Tolvaptan works by blocking the action of vasopressin, a hormone that causes the kidneys to retain water. By blocking this hormone, tolvaptan helps the body remove excess water while retaining sodium, which can help correct sodium imbalances and reduce fluid overload. Key points for patients: Tolvaptan is usually started in a hospital setting so your doctor can monitor your sodium levels and kidney function. It is important to drink water only when you are thirsty while taking this medication, and to follow your healthcare provider’s instructions closely.

Therapeutic uses

  • Hyponatremia in patients with heart failure
  • Hyponatremia in patients with syndrome of inappropriate antidiuretic hormone (SIADH)
  • Autosomal dominant polycystic kidney disease (ADPKD)

Common side effects

  • Thirst
  • Polyuria
  • Nocturia
  • Dry mouth
  • Constipation
  • Hypernatremia
  • Liver injury

Frequently Asked Questions about Tolvaptan

What is tolvaptan used for?

Tolvaptan is used to treat low blood sodium (hyponatremia) due to heart failure or SIADH, and to slow kidney function decline in adults with autosomal dominant polycystic kidney disease (ADPKD).

How does tolvaptan work?

Tolvaptan blocks the action of vasopressin, a hormone that causes the kidneys to retain water. By blocking vasopressin, tolvaptan helps the body remove excess water while retaining sodium.

What are the most common side effects?

The most common side effects are thirst, dry mouth, increased urination, constipation, and weakness.

Can I take tolvaptan if I have liver disease?

Tolvaptan can cause serious liver injury and should be used with caution in patients with liver disease. Regular liver function monitoring is required.

Is tolvaptan safe during pregnancy or breastfeeding?

Tolvaptan is not recommended during pregnancy or breastfeeding unless clearly needed. Discuss with your healthcare provider.

What should I do if I miss a dose?

Take the missed dose as soon as you remember, unless it is almost time for your next dose. Do not double up doses.

Are there any foods or drugs I should avoid while taking tolvaptan?

Avoid grapefruit or grapefruit juice, and avoid strong CYP3A inhibitors such as ketoconazole, clarithromycin, or ritonavir.

Educational information only. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.