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Samsca
Tolvaptan
$5850.00
15mg · 9 × 10 tablets · 3 months supply
BrandBranded medicine
$1950.00 per month
How long a supply?
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Annual cost
$24050a year at this pack size
Prescription required
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FDA boxed warning(a) initiate and re-initiate in a hospital and monitor serum sodium (b) not for use for autosomal dominant polycystic kidney disease (adpkd)
(A) Initiate and re-initiate in a hospital and monitor serum sodium
SAMSCA should be initiated and re-initiated in patients only in a hospital where serum sodium can be monitored closely.
Too rapid correction of hyponatremia (e.g., >12 mEq/L/24 hours) can cause osmotic demyelination resulting in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma and death. In susceptible patients, including those with severe malnutrition, alcoholism or advanced liver disease, slower rates of correction may be advisable.
(B) Not for use for autosomal dominant polycystic kidney disease (ADPKD)
Because of the risk of hepatotoxicity, tolvaptan should not be used for ADPKD outside of the FDA-approved REMS
About Samsca
Overview
Samsca contains tolvaptan, a medicine used to treat clinically significant low blood sodium when the body has normal or excess fluid levels, including in people with heart failure or syndrome of inappropriate antidiuretic hormone (SIADH). It blocks the action of vasopressin at V2 receptors, helping the body pass more water in urine and raising blood sodium levels. It is not for people who need their blood sodium raised urgently to prevent or treat serious neurological symptoms. It has not been established that Samsca improves symptoms.
What it treats
- Clinically significant low blood sodium (hyponatremia) in people with excess or normal body fluid levels, including those with heart failure or syndrome of inappropriate antidiuretic hormone (SIADH). This means blood sodium below 125 mEq/L, or less severe low sodium that causes symptoms and has not improved with fluid restriction. Samsca is not for patients who need an urgent increase in blood sodium to prevent or treat serious neurological symptoms. It has not been established that Samsca improves symptoms.
Safety information
Side effects
Common side effects include thirst, dry mouth, weakness, constipation, frequent urination or passing more urine, and high blood sugar. Serious risks include liver injury, dehydration and low blood volume. Contact a doctor promptly if any of these are suspected or if you have trouble passing urine. Your doctor may need to monitor your blood potassium if it is already high or you take medicines that increase it.
FDA boxed warning
(a) initiate and re-initiate in a hospital and monitor serum sodium (b) not for use for autosomal dominant polycystic kidney disease (adpkd)
(A) Initiate and re-initiate in a hospital and monitor serum sodium
SAMSCA should be initiated and re-initiated in patients only in a hospital where serum sodium can be monitored closely.
Too rapid correction of hyponatremia (e.g., >12 mEq/L/24 hours) can cause osmotic demyelination resulting in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma and death. In susceptible patients, including those with severe malnutrition, alcoholism or advanced liver disease, slower rates of correction may be advisable.
(B) Not for use for autosomal dominant polycystic kidney disease (ADPKD)
Because of the risk of hepatotoxicity, tolvaptan should not be used for ADPKD outside of the FDA-approved REMS
A boxed warning is the strongest warning the US Food and Drug Administration requires on a medicine label. Text is taken from the official label, with internal section references removed.
When to call your doctor
If symptoms are severe or getting worse quickly, seek emergency care rather than waiting.
Before taking this medicine
Do not take Samsca if you: • Cannot sense thirst or respond appropriately to it. • Have low blood sodium together with low blood volume (hypovolemic hyponatremia). • Do not produce urine (anuria). • Take a strong CYP3A inhibitor. • Are allergic to tolvaptan or any ingredient in Samsca. • Have autosomal dominant polycystic kidney disease (ADPKD), unless treatment is within an FDA-approved Risk Evaluation and Mitigation Strategy (REMS) programme. Samsca can cause liver injury. Treatment must be limited to 30 days, and it must be stopped if liver injury is suspected. Avoid use if you have underlying liver disease. Dehydration and low blood volume may require medical intervention. Avoid use with hypertonic saline or moderate CYP3A inhibitors. Blood potassium should be monitored if your potassium is above 5 mEq/L or you take medicines that increase it. If you have a blockage affecting urine flow, urine must be able to drain before treatment. Samsca may harm an unborn baby. Breastfeeding is not recommended during treatment. There are no studies of its use in children.
Interactions
Avoid taking Samsca (tolvaptan) with medicines classed as moderate CYP3A inhibitors, strong CYP3A inducers or other V2-receptor antagonists. Ask your doctor or pharmacist to check whether any of your medicines belong to these groups. Blood potassium levels should be monitored if Samsca is taken with angiotensin receptor blockers (ARBs), angiotensin-converting enzyme (ACE) inhibitors or potassium-sparing diuretics.
Using Samsca
Dosing
Dosing is set by your prescriber. Each health care professional may prescribe medication differently according to a patient's medical history and condition, so follow the directions on your prescription label and speak to your doctor or pharmacist before changing anything.
Storage
Store below 25°C in a dry place, in the original pack, away from direct light and moisture. Do not keep it in a bathroom. Keep all medicines out of the sight and reach of children.
Clinical information on this page is summarised from the US FDA label SAMSCA (TOLVAPTAN) TABLET [OTSUKA AMERICA PHARMACEUTICAL, INC.] (DailyMed, retrieved 19 September 2026).
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