Generic Name: tolvaptan
(tol VAP tan)

What is Samsca?

Samsca 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.

Samsca 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.

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

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

You should not use this medication if you are allergic to Samsca, 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 should not take Samsca if you are using certain other medications. Before you take 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 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 Samsca in a hospital setting where your heart rhythm can be monitored, in case the medication causes serious side effects.

If you stop taking Samsca 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).

Drink plenty of fluids during the first 24 hours of treatment with Samsca. Avoid alcoholic drinks. Follow your doctor’s instructions about the type and amount of liquids you should drink while treating hyponatremia. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

To be sure this medication is helping your condition, your blood will need to be tested on a regular basis. You may not notice any change in your symptoms, but your blood work will help your doctor determine how long to treat you with Samsca.

What should I discuss with my health care provider before taking Samsca?

You should not use this medication if you are allergic to Samsca, 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 should not take Samsca if you are taking any of the following medications:

• conivaptan (Vaprisol)
• an antibiotic such as clarithromycin (Biaxin), dalfopristin/quinupristin (Synercid), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin), or telithromycin (Ketek)
• antifungal medication such as fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), or voriconazole (Vfend)
• an antidepressant such as nefazodone
• heart or blood pressure medication such as diltiazem (Cardizem, Dilacor, Tiazac), nicardipine (Cardene), quinidine (Quinaglute, Quinidex, Quin-Release), or verapamil (Calan, Covera, Isoptin, Verelan); or
• HIV/AIDS medicine such as amprenavir (Agenerase), atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), saquinavir (Invirase), or ritonavir (Norvir).

Your doctor will tell you if any of your medications need to be changed while taking Samsca.

If you have any of these other conditions, you may need a dose adjustment or special tests to safely take Samsca:

• severe liver disease (especially cirrhosis)
• if you are malnourished; or
• if you have been drinking large amounts of alcohol.

FDA pregnancy category C. It is not known whether Samsca is harmful to an unborn baby. Before taking this medication, tell your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known whether Samsca passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take Samsca?

Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.

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

Your doctor may occasionally change your dose to make sure you get the best results from this medication.

Samsca is usually given once per day, with or without food.

Take this medication with a full glass (8 ounces) of water. Drink plenty of fluids during the first 24 hours of treatment with Samsca. It is best to drink something as soon as you feel thirsty, but avoid alcoholic drinks. Follow your doctor’s instructions about the type and amount of liquids you should drink while treating hyponatremia. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

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.

To be sure this medication is helping your condition, your blood will need to be tested on a regular basis. You may not notice any change in your symptoms, but your blood work will help your doctor determine how long to treat you with Samsca.

If you stop taking Samsca 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.

Store Samsca at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do nottake extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine. Overdose can cause dehydration (weakness, extreme thirst, increased urination, decreased sweating, hot or dry skin).

What should I avoid while taking Samsca?

Grapefruit and grapefruit juice may interact with Samsca and lead to potentially dangerous effects. Avoid drinking grapefruit juice while taking tolvaptan.

What are the possible side effects of 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).

Copyright 1996-2009 Cerner Multum, Inc. Version: 1.03. Revision date: 09/09/2009.