Tolvaptan

Jynarque helps slow down the loss of kidney function in adults with autosomal dominant polycystic kidney disease.

Jynarque is available only through a special program. You must be registered in the program and understand the risks and benefits of tolvaptan.

Samsca is used to treat adults with hyponatremia (low sodium levels in your blood) in people with heart failure and some hormonal imbalances.

Tolvaptan may also be used for other reasons not mentioned in this medication guide.

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

Drink plenty of fluids while taking tolvaptan, but do not drink grapefruit juice or alcoholic drinks.

You may take tolvaptan with or without food.

Samsca is usually taken once per day and Jynarque is taken twice per day. You should not use Samsca for longer than 30 days. Follow your doctor's dosing instructions very carefully.

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

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

You will need frequent medical tests.

Store at room temperature away from moisture and heat.

Tell your doctor about all the medicines you are currently taking and any that you start or stop. Many drugs can interact with each other, and some should never be used together.

Samsca is used to treat low sodium levels in your blood, but reversing this condition too quickly can be dangerous. Inform your caregivers immediately if you have issues with speech or muscle control, difficulty swallowing, trouble moving your arms and legs, confusion, or seizures.

Tolvaptan can lead to serious or fatal liver problems. Contact your doctor right away if you feel unwell and have pain in the upper right side of your stomach, vomiting, loss of appetite, or yellowing of your skin or eyes.

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

• you cannot urinate;
• you cannot tell that you are thirsty; or
• you are severely dehydrated and feel like you might pass out.

Samsca is not for use in people with autosomal dominant polycystic kidney disease (unless you receive Samsca through a special program that includes frequent liver function tests).

You should not take Samsca if your sodium level needs to be increased quickly.

You should not take Jynarque if you have been told that your sodium blood level is too high or too low, or if you have liver problems, excluding polycystic liver disease.

Some drugs should not be used with Samsca. Your treatment plan may change if you also use:

• nefazodone;
• an antibiotic--clarithromycin, telithromycin;
• antifungal medicine--itraconazole, ketoconazole; or
• HIV/AIDS medication--indinavir, nelfinavir, ritonavir, saquinavir.

Tell your doctor if you have or have ever had:

• any allergies;
• if you drink large amounts of alcohol;
• if you are malnourished (if you are taking Samsca);
• if you also use desmopressin (dDAVP), or a diuretic or "water pill";
• liver problems; or
• kidney disease or urination problems.

It is not known if tolvaptan will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Do not breastfeed.

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

Tolvaptan may cause serious side effects. Call your doctor immediately if you have:

• weakness, or feeling light-headed (like you might faint);
• irregular heartbeats;
• weight loss;
• dehydration--dizziness, confusion, feeling very thirsty, urinating less; or
• liver problems--loss of appetite, nausea, vomiting, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Samsca is given to treat low sodium levels in your blood, but it can be dangerous if your sodium level rises too quickly. Tell your doctor or caregivers right away if you have any of these signs that your hyponatremia is being corrected too rapidly:

• problems with speech or muscle control;
• trouble swallowing;
• difficulty moving your arms and legs;
• drowsiness, confusion, mood changes; or
• a seizure.

Common side effects of tolvaptan may include:

• dry mouth;
• increased thirst or urination;
• hunger, fruity breath odor;
• 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.

Usual Adult Dose for Hyponatremia:

Initial dose: 15 mg orally once a day Maintenance dose: Increase the dose to 30 mg once a day, after at least 24 hours, to a maximum of 60 mg once a day, as needed to achieve the desired level of serum sodium. Maximum dose: 60 mg once a dayDuration of therapy: Maximum of 30 daysComments:-During initiation and titration, frequently monitor for changes in serum electrolytes and volume. -Avoid fluid restriction during the first 24 hours of therapy. -Patients receiving tolvaptan should be advised that they can continue ingestion of fluid in response to thirst.-Tolvaptan may be dosed without regard to meals.Uses: Hypervolemic and euvolemic hyponatremia [serum sodium less than 125 mEq/L or less marked hyponatremia that is symptomatic and has resisted correction with fluid restriction], including patients with heart failure, and Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Usual Adult Dose for Hyponatremia, euvolemic:

Initial dose: 15 mg orally once a day Maintenance dose: Increase the dose to 30 mg once a day, after at least 24 hours, to a maximum of 60 mg once a day, as needed to achieve the desired level of serum sodium. Maximum dose: 60 mg once a dayDuration of therapy: Maximum of 30 daysComments:-During initiation and titration, frequently monitor for changes in serum electrolytes and volume. -Avoid fluid restriction during the first 24 hours of therapy. -Patients receiving tolvaptan should be advised that they can continue ingestion of fluid in response to thirst.-Tolvaptan may be dosed without regard to meals.Uses: Hypervolemic and euvolemic hyponatremia [serum sodium less than 125 mEq/L or less marked hyponatremia that is symptomatic and has resisted correction with fluid restriction], including patients with heart failure, and Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Samsca: Take the medicine as soon as you can, but if it is almost time for your next dose, skip the missed dose.

Jynarque: If you miss a dose, skip it and take your next dose at the regular time.

Do not take two doses at the same time.

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

Avoid drinking alcohol.

Grapefruit may interact with tolvaptan and cause side effects. Avoid consuming grapefruit products.

Sometimes it is not safe to use certain medicines together. Some drugs can change the levels of other drugs in your blood, which may increase side effects or reduce the effectiveness of the medicines.

Many drugs can affect tolvaptan, and some should not be taken at the same time. Inform your doctor about all other medicines you are using. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are mentioned here.

• What is the difference between Jynarque (tolvaptan) and Samsca (tolvaptan)?