Tolvaptan 15mg Tablets — Generic Samsca® 15mg | Order Online

Tolvaptan 15mg Tablets are a prescription medicine containing tolvaptan 15mg as the active ingredient and the generic equivalent of Samsca® 15mg, the reference brand product developed by Otsuka Pharmaceutical. Tolvaptan is a selective vasopressin V2 receptor antagonist — a class of medicine known as vaptans or aquaretics — that promotes free water excretion without significant loss of electrolytes. Generic tolvaptan 15mg tablets are used primarily in the treatment of clinically significant hyponatraemia (abnormally low blood sodium) and, under the separate brand Jinarc®, for slowing kidney cyst growth in autosomal dominant polycystic kidney disease (ADPKD). Tolvaptan 15mg is available internationally across the USA, UK, Australia, UAE, Germany, France, Russia, South Korea and worldwide.

Product Information

What Is Tolvaptan 15mg Used For?

Tolvaptan 15mg has two distinct approved indications depending on the market and the specific brand or generic product. These are separate regulatory pathways and the indications are not interchangeable between products without prescriber direction.

Hyponatraemia — Samsca® indication

Tolvaptan 15mg (Samsca®) is indicated for the treatment of clinically significant euvolaemic and hypervolaemic hyponatraemia — low blood sodium associated with:

• Heart failure
• Hepatic cirrhosis
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH)

In the USA, Samsca® is FDA-approved for the treatment of clinically significant hypervolaemic and euvolaemic hyponatraemia (serum sodium below 125 mEq/L, or less marked hyponatraemia that is symptomatic and resistant to correction with fluid restriction) in hospitalised patients.

In the UK and EU, tolvaptan (Samsca®) is indicated for the treatment of adult patients with hyponatraemia secondary to SIADH.

ADPKD — Jinarc® indication

In the UK, EU and other markets, Jinarc® (tolvaptan) is separately approved for slowing the progression of cyst development and renal insufficiency in adults with ADPKD at risk of rapid disease progression. This is a distinct product and indication from Samsca® with its own prescribing programme and hepatotoxicity risk management requirements.

In the USA, the ADPKD indication is approved under the brand Jynarque®.

Australia: Tolvaptan products are registered on the ARTG for relevant indications. PBS subsidisation depends on specific indication and eligibility — confirm with your prescriber.

UAE / Gulf: Subject to UAE Ministry of Health registration. Consult a UAE-licensed physician for current tolvaptan 15mg UAE availability.

Germany: Tolvaptan 15mg is available as Samsca® 15mg and Jinarc® 15mg. Generic tolvaptan 15mg products may also be available. All are prescription-only (rezeptpflichtig).

France: Tolvaptane 15mg is available as Samsca® and Jinarc® in France, subject to prescription and HAS reimbursement.

Russia: Толваптан 15 мг is available as Самска® 15 мг in Russia. All products require a valid prescription.

South Korea: 톨밥탄 15mg is registered for prescription use per MFDS-approved labeling.

Always follow the prescribing information applicable to your country and the guidance of your licensed healthcare professional.

How Tolvaptan 15mg Works

Tolvaptan selectively blocks the vasopressin V2 receptor in the collecting ducts of the kidney. Vasopressin (also called antidiuretic hormone, ADH) normally acts on V2 receptors to promote water reabsorption, concentrating the urine and retaining water in the body.

By blocking this receptor, tolvaptan causes aquaresis — the selective excretion of free water without significant accompanying sodium or potassium loss. This is the key distinction between tolvaptan and conventional diuretics such as furosemide or hydrochlorothiazide, which cause loss of both water and electrolytes.

In hyponatraemia:

• Aquaresis increases serum sodium concentration by removing excess free water
• The rate of sodium correction must be carefully controlled to avoid osmotic demyelination syndrome

In ADPKD:

• Vasopressin stimulates cAMP-mediated cyst growth in polycystic kidneys
• Blocking V2 receptors reduces cAMP signalling in cystic epithelial cells, slowing cyst enlargement and preserving kidney function

Tolvaptan 15mg vs 30mg vs 60mg — Dose Overview

Tolvaptan is available in multiple strengths. The 15mg strength is relevant to both indications:

Samsca® dosing (hyponatraemia):

• Initiation: 15mg once daily — must be started in hospital with serum sodium monitoring
• Titration: may be increased to 30mg, then 60mg once daily at 24-hour intervals if needed and tolerated
• The 15mg dose is the mandatory starting dose — never initiate at a higher dose

Jinarc® / Jynarque® dosing (ADPKD):

• Titration schedule involves split daily dosing (morning and evening)
• Starting doses differ from the Samsca® schedule — refer to the specific ADPKD prescribing information

Do not adjust your tolvaptan dose without guidance from your specialist.

Key Safety Information — Tolvaptan 15mg

Hepatotoxicity — Serious Liver Injury Risk

Tolvaptan can cause serious and potentially fatal liver injury, including acute liver failure requiring transplantation. This risk is greatest with the ADPKD indication (Jinarc®/Jynarque®) and long-term use, but hepatotoxicity has also been reported with Samsca®.

Signs of liver injury include:

• Unusual fatigue or weakness
• Loss of appetite, nausea or vomiting
• Abdominal pain (particularly right upper quadrant)
• Jaundice (yellowing of skin or eyes)
• Dark urine

Patients must not take tolvaptan for longer than 30 days in the hyponatraemia indication (Samsca®/USA labeling restriction) due to hepatotoxicity risk. For ADPKD use (Jinarc®/Jynarque®), a formal Risk Evaluation and Mitigation Strategy (REMS) programme applies in the USA, and an equivalent risk management programme applies in the UK/EU.

Osmotic Demyelination Syndrome (ODS)
Too-rapid correction of hyponatraemia with tolvaptan can cause osmotic demyelination syndrome — a potentially irreversible neurological condition. Serum sodium must be monitored closely, particularly within the first 24 hours of initiation. Tolvaptan must be initiated only in a hospital setting where sodium levels can be monitored and managed.

Contraindications
Tolvaptan 15mg must not be used in patients with:

• Urgent need to raise serum sodium acutely
• Inability to sense or respond appropriately to thirst
• Hypovolaemic hyponatraemia
• Hepatic impairment (varies by indication — refer to local SPC/PI)
• Concurrent use of strong CYP3A4 inhibitors (e.g. ketoconazole, itraconazole, clarithromycin, ritonavir)
• Anuria
• Known hypersensitivity to tolvaptan or any excipient

Drug Interactions

• Strong and moderate CYP3A4 inhibitors — significantly increase tolvaptan exposure (contraindicated or use with caution)
• CYP3A4 inducers — reduce tolvaptan efficacy
• P-glycoprotein inhibitors — may increase tolvaptan levels
• Loop diuretics and other diuretics — additive aquaretic/diuretic effect
• Hypertonic saline — concurrent use not recommended (risk of overly rapid sodium correction)

Fluid Intake
Patients must have unrestricted access to water during tolvaptan treatment. Restriction of fluid intake during treatment can lead to dangerous dehydration and hypernatraemia.

Always read the patient information leaflet and prescribing information applicable to your country before taking tolvaptan.

Tolvaptan 15mg — Availability by Country

Frequently Asked Questions — Tolvaptan 15mg

What is Tolvaptan 15mg used for?
Tolvaptan 15mg is used to treat clinically significant hyponatraemia (low blood sodium) associated with heart failure, hepatic cirrhosis and SIADH. Under a separate brand (Jinarc®/Jynarque®), tolvaptan is also used to slow kidney cyst progression in ADPKD. Indications and approved uses vary by country.

Is Tolvaptan 15mg the generic for Samsca® 15mg?
Yes. Samsca® 15mg is the originator brand containing tolvaptan 15mg for the hyponatraemia indication. Generic tolvaptan 15mg tablets contain the same active ingredient and strength. Inactive ingredients, appearance and manufacturer may differ.

What is the difference between Samsca® and Jinarc®?
Both contain tolvaptan but are approved for different indications under separate regulatory pathways. Samsca® is for hyponatraemia. Jinarc® (Jynarque® in the USA) is for ADPKD. They have different dosing schedules and risk management requirements. They are not interchangeable.

Why must Tolvaptan 15mg be started in hospital?
Tolvaptan must be initiated in a hospital because it can correct serum sodium too rapidly, causing osmotic demyelination syndrome — a serious and potentially irreversible neurological complication. Sodium levels must be monitored closely during the first 24 hours of treatment.

Can Tolvaptan 15mg cause liver damage?
Yes. Tolvaptan can cause serious and potentially fatal hepatotoxicity, including acute liver failure. Liver function must be monitored during treatment. Contact your doctor immediately if you develop symptoms of liver injury such as unusual fatigue, nausea, abdominal pain, dark urine or jaundice.

Does Tolvaptan 15mg interact with other medicines?
Yes. Tolvaptan is significantly affected by CYP3A4 inhibitors and inducers. Strong CYP3A4 inhibitors including ketoconazole, itraconazole, ritonavir and clarithromycin are contraindicated with tolvaptan. Always provide your doctor with a full list of current medicines.

Can I buy Tolvaptan 15mg tablets online?
Tolvaptan 15mg is prescription-only in the USA, UK, Australia, UAE and most markets worldwide. Due to the hepatotoxicity and sodium monitoring requirements, it must be initiated under direct medical supervision.

Is Tolvaptan 15mg available in Australia?
Tolvaptan products are registered on the ARTG. PBS subsidisation depends on specific indication and eligibility. Confirm current status with your prescriber or pharmacist.

What is the difference between Tolvaptan 15mg and 30mg?
Tolvaptan 15mg is the mandatory starting dose for the hyponatraemia indication (Samsca®). It may be increased to 30mg after 24 hours if sodium correction is inadequate and the medicine is tolerated. Do not self-adjust your dose.

Is Tolvaptan a diuretic?
Tolvaptan is classified as an aquaretic rather than a conventional diuretic. It promotes selective free water excretion without significant sodium or potassium loss, unlike loop diuretics such as furosemide or thiazide diuretics such as hydrochlorothiazide.

Medical Disclaimer

This information is provided for educational and commercial reference purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Tolvaptan 15mg is a prescription-only medicine with serious hepatotoxicity risk and strict monitoring requirements. It must be initiated in a hospital setting where serum sodium can be closely monitored. Always use it according to the applicable prescribing information and the advice of a qualified healthcare professional licensed in your country.

Last Updated: September 25, 2026