Treatment with this drug should be started or restarted in a hospital for proper monitoring. Too rapid correction of low levels of sodium in the blood may rarely result in a serious (rarely fatal) condition - osmotic demyelination syndrome (ODS). Tell your doctor right away if you notice any of the following symptoms of ODS: trouble speaking/swallowing, mental/mood changes (such as confusion), weakness/involuntary movement in the arms/legs, or seizures.
This medication is used to treat low levels of salt (sodium) in the blood, which can result from conditions such as heart failure and certain hormone imbalances. Tolvaptan belongs to a class of drugs known as vasopressin receptor antagonists. It works by increasing the amount of urine you make, causing your body to get rid of extra water. This helps to slowly increase to normal levels of salt (sodium) in the blood.
Read the Medication Guide provided by your pharmacist before you start using tolvaptan and each time you get a refill. If you have any questions, consult your doctor or pharmacist.
Take this medication by mouth with or without food, usually once daily or as directed by your doctor. You should not take tolvaptan for longer than 30 days.
To prevent losing too much body water (dehydration), have water available to drink at all times while taking tolvaptan. Drink when you are thirsty unless otherwise directed by your doctor.
Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day. Do not stop and restart this medication on your own. You may need to go back to a hospital to restart this medication. Tell your doctor right away if you stop taking this medication for any reason.
Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor instructs you otherwise. Grapefruit can increase the amount of this medication in your bloodstream. Consult your doctor or pharmacist for more details.
Dosage is based on your medical condition and response to treatment.
See also Warning section.
Thirst, dry mouth, loss of appetite, constipation, or weakness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Loss of too much body water (dehydration) can occur. The risk is increased if you have persistent vomiting or diarrhea, and cannot drink normally. Contact your doctor right away if you notice any symptoms of dehydration, such as fast heartbeat or dizziness/lightheadedness.
People with severe liver disease (cirrhosis) may have increased risk of bleeding from the stomach or intestines while taking this medication. Tell your doctor right away if you have any of the following symptoms: black/bloody stools, vomit that contains blood or looks like coffee grounds.
Tolvaptan may rarely cause serious (possibly fatal) liver disease. Get medical help right away if you have any symptoms of liver damage, including: dark urine, persistent nausea/vomiting/loss of appetite, stomach/abdominal pain, yellowing eyes/skin.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking tolvaptan, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: diabetes, liver disease, inability to make urine (anuria), use/abuse of alcohol.
To prevent loss of too much body water (dehydration) while taking this medication, you must be able to replace fluids by drinking. Before taking this medication, tell your doctor if you are not able to drink normally or if you cannot feel if you are thirsty. (See also How to Use section.)
This medication may rarely make your blood sugar level rise, which can cause or worsen diabetes. If you have diabetes, be sure to check your blood sugar regularly. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
It is unknown if this medication passes into breast milk. Consult your doctor before breast-feeding.
See also How to Use section.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
A product that may interact with this drug is: desmopressin.
Other medications can affect the removal of tolvaptan from your body, which may affect how tolvaptan works. Examples include azole antifungals (such as ketoconazole), cobicistat, HIV protease inhibitors (such as lopinavir, ritonavir), macrolide antibiotics (such as erythromycin), rifamycins (such as rifabutin), St. John's Wort, drugs used to treat seizures (such as carbamazepine, phenytoin), among others.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
Do not share this medication with others.
Laboratory and/or medical tests (such as levels of sodium/potassium in the blood) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature between 59-86 degrees F (15-30 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your medication.
Information last revised July 2016. Copyright(c) 2016 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet