Drugs A - Z

Tolvaptan Oral tablet

It is used to treat low levels of sodium in the blood.

Generic Name: tolvaptan

Brand Names: Samsca

What is this medicine?

TOLVAPTAN (tol VAP tan) is used to treat low levels of sodium in the blood.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
  • can not feel if you are thirsty
  • diarrhea or vomiting
  • if you frequently drink alcohol containing drinks
  • kidney disease and your body can not make urine
  • liver disease
  • not eaten enough for a long period of time (malnourished)
  • an unusual or allergic reaction to tolvaptan, other medicines, foods, dyes, or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. This medicine will be started in a hospital. You may need to continue this medicine at home. Follow the directions on the prescription label. Do not stop and re-start this medicine on your own. You may need to go back to a hospital to re-start this medicine. You can take it with or without food. If it upsets your stomach, take it with food. Take your medicine at regular intervals. Do not take it more often than directed. Do not stop taking except on your doctor's advice.

A special MedGuide will be given to you by the pharmacist with each prescription and refill. Be sure to read this information carefully each time.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.


Overdosage: If you think you've taken too much of this medicine contact a poison control center or emergency room at once.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following medications:
  • clarithromycin
  • delavirdine
  • dalfopristin; quinupristin
  • indinavir
  • isoniazid
  • itraconazole
  • ketoconazole
  • nefazodone
  • nelfinavir
  • ritonavir
  • saquinavir
  • telithromycin
  • tipranavir

This medicine may also interact with the following medications:

  • aprepitant
  • cyclosporine
  • digoxin
  • diuretics
  • erythromycin
  • grapefruit juice
  • medicines for blood pressure
  • medicines for seizures like carbamazepine, phenobarbital, phenytoin
  • medicines for tuberculosis like rifampin, rifabutin, and rifapentine
  • some medicines for fungal infections like fluconazole, miconazole, voriconazole
  • St. John's Wort

What should I watch for while using this medicine?

Your condition will be monitored carefully while you are receiving this medicine.

To prevent dehydration, have water available to drink at all times while taking this medicine. Drink when you are thirsty, unless your doctor or healthcare professional tells you otherwise.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • black or tarry stools
  • chest pain
  • confusion
  • fast, irregular heartbeat
  • mood changes
  • seizures
  • trouble speaking
  • uncontrollable body movements
  • unusually weak or tired
  • vomiting blood

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

  • constipation
  • dry mouth
  • increased hunger or thirst
  • increased urination


Last Updated: September 14, 2009
Licensed from
The Healthline Site, its content, such as text, graphics, images, search results, HealthMaps, Trust Marks, and other material contained on the Healthline Site ("Content"), its services, and any information or material posted on the Healthline Site by third parties are provided for informational purposes only. None of the foregoing is a substitute for professional medical advice, examination, diagnosis, or treatment. Always seek the advice of a physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the Healthline Site. If you think you may have a medical emergency, call your doctor or 911 immediately. Please read the Terms of Service for more information regarding use of the Healthline Site.
Advertisement