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tolvaptan (Samsca)

Brand Names: Samsca

Generic Name: tolvaptan

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, 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 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;
  • confusion, mood changes; or
  • a seizure.

While taking tolvaptan at home, call your doctor at once if you have:

  • weakness, or a light-headed feeling (like you might pass out);
  • liver problems--right-sided upper stomach pain, vomiting, loss of appetite, yellowing of your skin or eyes, not feeling well; or
  • dehydration symptoms--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;
  • hunger, fruity breath odor, drowsiness, blurred vision;
  • constipation; or
  • weakness.

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 will need to be in a hospital under observation any time you start or restart treatment with tolvaptan.

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact, and some drugs should not be used together.

Tell your caregivers at once if you have signs that your hyponatremia is being reversed too quickly: problems with speech or muscle control, trouble swallowing, trouble moving your arms and legs, confusion, or seizure.

While taking tolvaptan at home, call your doctor if you have signs of liver problems, such as: loss of appetite, upper stomach pain, dark urine, or jaundice (yellowing of the skin or eyes).

What should I discuss with my healthcare provider before taking tolvaptan (Samsca)?

You should not use tolvaptan if you are allergic to it, or if:

  • you are unable to urinate;
  • you are unable to tell that you are thirsty;
  • you are severely dehydrated and feel like you might pass out; or
  • you have autosomal dominant polycystic kidney disease (unless you receive tolvaptan through a special program that includes frequent liver function tests).

Some medicines can cause unwanted or dangerous effects when used with tolvaptan. Your doctor may change your treatment plan if you also use:

Tell your doctor if:

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant.

It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.

How should I take tolvaptan (Samsca)?

You will receive your first dose in a hospital or clinic setting to quickly treat any serious side effects.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Long-term use of tolvaptan can damage your liver or cause death. You should not use tolvaptan for longer than 30 days.

You may take tolvaptan with or without food.

Take this medicine with a full glass (8 ounces) of water. Drink plenty of fluids during the first 24 hours of taking tolvaptan, but avoid alcoholic drinks. Follow your doctor's instructions about the type and amount of liquids you should drink while treating hyponatremia.

Call your doctor if you have ongoing vomiting or diarrhea, or if you are sweating more than usual. You can easily become dehydrated while taking this medication, which can lead to serious side effects.

You will need frequent medical tests.

Store at room temperature away from moisture and heat.

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.

What happens if I miss a dose (Samsca)?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose (Samsca)?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking tolvaptan (Samsca)?

Avoid alcoholic drinks.

Grapefruit may interact with tolvaptan and lead to unwanted side effects. Avoid the use of grapefruit products.

What other drugs will affect tolvaptan (Samsca)?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect tolvaptan, and some drugs should not be used at the same time. Tell your doctor about all your current medicines and any medicine you start or stop using. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

Where can I get more information (Samsca)?

Your pharmacist can provide more information about tolvaptan.


Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

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