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Medications and Drugs

Brand Names: Samsca

Generic Name: tolvaptan (Pronunciation: tol VAP tan)

What is tolvaptan (Samsca)?

Tolvaptan reduces the level of a hormone that regulates the balance of water and salt (sodium) in the body. High levels of this hormone can cause an imbalance that results in low sodium levels and fluid retention.

Tolvaptan is used to treat hyponatremia (low levels of sodium in your blood) in people with heart failure, liver disease, and certain hormonal imbalances. Tolvaptan improves urine flow without causing the body to lose too much sodium as you urinate.

Tolvaptan may also be used for purposes not listed in this medication guide.

What are the possible side effects of tolvaptan (Samsca)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your caregivers at once if you have any of these signs that your hyponatremia is being reversed too quickly:

  • problems with speech or muscle control;
  • trouble swallowing;
  • trouble moving your arms and legs;
  • mood changes; and
  • seizure (convulsions).

Stop using tolvaptan and call your doctor at once if you have:

  • weakness or fainting;
  • black, bloody, or tarry stools;
  • coughing up blood or vomit that looks like coffee grounds;
  • nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
  • dehydration (feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin).

Common side effects may include:

  • dry mouth;
  • increased thirst or urination;
  • constipation; or
  • loss of appetite, fruity breath odor, drowsiness, dry skin, nausea, vomiting.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about tolvaptan (Samsca)?

You should not use this medication if you are allergic to tolvaptan, if you are unable to urinate, if you are unable to tell that you are thirsty, or if you are severely dehydrated and feel like you might pass out.

You may need to stop taking certain drugs while you are taking tolvaptan. Tell your doctor about all other medications you use. Your doctor will tell you if any of your medications need to be changed while taking tolvaptan.

Also tell your doctor if you have kidney disease, severe liver disease or cirrhosis, if you have been drinking large amounts of alcohol, or if you are malnourished.

You will receive your first few doses of tolvaptan in a hospital setting where your heart rhythm can be monitored, in case the medication causes serious side effects.

If you stop taking tolvaptan for any length of time, do not start taking it again at home. You will need to be in a hospital under observation any time you start or restart treatment with tolvaptan.

Tell your caregivers at once if you have any of these signs that your hyponatremia is being reversed too quickly: problems with speech or muscle control, trouble swallowing, trouble moving your arms and legs, mood changes, and seizure (convulsions).

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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