Samska OD (Tolvaptan) 15 mg, 20 tablets: profile, composition and research

Reference page for Samska OD (Tolvaptan) 15 mg, 20 tablets. Active substance: Толваптан / Tolvaptan.

Key facts

What tolvaptan is

Tolvaptan regulates the balance of water and salts in the body. Its job is to help the kidneys remove excess fluid without causing a marked loss of sodium. That is what sets it apart from ordinary diuretics, which carry sodium out together with water.

It is usually prescribed for hyponatraemia, a low level of sodium in the blood. In this state the body retains water and the sodium concentration becomes diluted. Most often it is linked to heart failure or to a disturbance in the production of the hormone that controls water excretion.

Samska OD comes as 15 mg tablets. The OD marking means the medicine is intended for once-daily use. The exact regimen is set by a physician, because what matters here is not only the dose but also the speed at which sodium returns to normal.

How tolvaptan works

The target in the kidney

The substance blocks type 2 vasopressin receptors. This hormone makes the kidneys hold on to water. Once the receptors are blocked, water is excreted more actively while sodium stays in the body.

Why it matters

Vasopressin is also called antidiuretic hormone. This is where the group name comes from: tolvaptan belongs to the vasopressin antagonists.

The main limitation

The sodium level has to rise gradually. Correcting it too quickly can damage nerve cells, so treatment is carried out with constant laboratory monitoring.

Approved uses

The prescribing information lists the conditions in which the body retains water and loses sodium. These are hyponatraemia in heart failure and hyponatraemia in the syndrome of inappropriate antidiuretic hormone secretion.

For patients with polycystic kidney disease there is a separate use, but it relies on a different brand and a special programme of liver monitoring. The two cases must not be mixed: the medicine for one task does not replace the medicine for the other.

Tolvaptan itself does not remove the cause of the underlying disease. It helps to correct the consequence, so it is used alongside treatment of the disease itself. The length of the course and the need for repeat courses are decided by a physician.

Why medical supervision is needed

Tolvaptan can affect the liver. Weakness, pain in the upper right abdomen, nausea, loss of appetite or yellowing of the skin should be reported to a doctor without delay.

Dehydration, an inability to pass urine and severe thirst are conditions in which the medicine is not used. Before treatment starts, a doctor checks whether any of these are present.

Regular blood tests and sodium checks are done during treatment. Difficulty with speech, swallowing or movement, confusion and seizures require immediate medical help.

Published research

Primary sources, verified against PubMed:

• Tolvaptan in heart failure: Contemporary evidence and a framework for precision decongestion., PubMed 42714631 (Heart Fail Rev, 2026).
• Serum Copeptin Rises After Tolvaptan for Hyponatraemia, but Does Not Predict Risk of Rapid Sodium Rise: Pre-Specified Secondary Analysis of the TVFR Trial., PubMed 42544815 (Clin Endocrinol (Oxf), 2026).

Listed for reference. Publication of a study is not a claim about this particular product.

Precautions

• This is a prescription medicine. Prescribing, dosing and monitoring belong to a physician.
• Tolvaptan can affect the liver. Weakness, pain in the upper right abdomen, loss of appetite or yellowing of the skin should be reported to a doctor at once.
• The medicine is not used in dehydration, inability to pass urine or severe thirst.
• Raising the sodium level too quickly is dangerous for the nervous system, so treatment runs with laboratory monitoring.
• Use during pregnancy or breastfeeding is discussed with a doctor individually.
• Tell your doctor about every other medicine you take: interactions are possible.

Frequently asked