Tolvaptan (low blood sodium)
Tolvaptan (Jynarque) is a prescription tablet used to slow the loss of kidney function in adults with a fast-progressing inherited kidney disease called ADPKD.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Tolvaptan can cause serious and potentially fatal liver damage. Cases of acute liver failure requiring a liver transplant have been reported in real-world use. This is not a rare theoretical risk — it is a known, documented danger. To catch problems early, you will need regular blood tests to check your liver before starting and throughout treatment (at 2 weeks, 4 weeks, monthly for 18 months, then every 3 months). Watch for warning signs like yellowing of the skin or eyes, dark urine, nausea, vomiting, fatigue, fever, rash, itching, or stomach pain on the right side — and report them to your doctor right away. Because of this serious risk, tolvaptan is only available through a special restricted distribution program (called a REMS), meaning your doctor and pharmacy must both be enrolled to prescribe and dispense it.
📖 Tolvaptan (low blood sodium): Patient Information Guide
A plain-language walkthrough of Tolvaptan (low blood sodium) — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Tolvaptan is prescribed to protect kidney function in people with a specific inherited kidney disease:
- Autosomal dominant polycystic kidney disease (ADPKD) — specifically in adults whose disease is progressing rapidly, to slow how quickly kidney function declines
⚙️How it works▾
Your kidneys normally respond to a hormone called vasopressin (ADH), which tells them to hold onto water. Tolvaptan blocks the specific docking site that vasopressin uses — called the V2 receptor. When that signal is blocked, the kidneys release more water into urine instead of retaining it. This also lowers levels of a chemical messenger inside kidney cells (cAMP), which in lab and animal studies slowed the growth and fluid accumulation inside the cysts that cause ADPKD damage.
Essentially, tolvaptan interrupts the hormonal chain that drives cyst growth, giving the kidneys a better chance of holding onto their function longer.
💊How it's taken▾
Tolvaptan is taken orally twice a day — one dose as soon as you wake up and a second, smaller dose 8 hours later. It can be taken with or without food, though a high-fat meal may affect how quickly it is absorbed. Your doctor will likely start you at a lower total daily dose and gradually increase it based on how well you tolerate the effects.
- Take doses at consistent times each day
- Drink plenty of water throughout the day to match the increased urine output and prevent dehydration
- If you miss a dose, skip it — take the next dose at its regular scheduled time; never double up
- If you are taking certain other medications (moderate CYP3A inhibitors), your dose may need to be reduced — ask your pharmacist
🤒Side effects — in detail▾
The most common side effects are directly related to how the drug works — it makes you urinate much more than usual:
- Intense thirst
- Frequent urination during the day (pollakiuria/polyuria)
- Waking up at night to urinate (nocturia)
- Drinking large amounts of fluid (polydipsia)
- Fatigue and nausea
- Signs of dehydration or high blood sodium (dizziness, weakness, confusion)
These water-loss effects are expected but can become dangerous if you don't drink enough fluids. Serious liver injury can also occur — stop the drug and call your doctor immediately if you notice yellow skin or eyes, dark urine, right-sided belly pain, vomiting, or unusual fatigue.
⚠️Warnings & precautions▾
- Serious liver injury: Tolvaptan can cause severe, potentially fatal liver damage. Liver transplants have been required in some cases. Regular blood tests are mandatory before and throughout treatment. Stop the drug and call your doctor at the first sign of liver trouble.
- Dehydration and high blood sodium (hypernatremia): Because this drug causes heavy water loss in urine, dehydration and elevated blood sodium can develop — especially if you don't drink enough. Stay well hydrated every day.
- Restricted access (REMS program): Because of the liver risk, tolvaptan is only dispensed through a special program. Both your prescriber and your pharmacy must be registered.
- Thirst must be intact: You must be able to feel thirst and act on it. People who cannot sense thirst should not take this drug.
🔀What it interacts with▾
Tolvaptan is broken down by a liver enzyme called CYP3A, so drugs that affect this enzyme can significantly change tolvaptan levels in your body:
- Strong CYP3A inhibitors (e.g., certain antifungals like ketoconazole) — can raise tolvaptan blood levels dramatically; must not be taken together
- Moderate CYP3A inhibitors — require a dose reduction of tolvaptan; ask your pharmacist if any of your medications fall into this category
- Strong CYP3A inducers (e.g., rifampin) — lower tolvaptan levels, making it less effective; avoid combining
- Grapefruit juice — can raise tolvaptan blood levels; avoid while on this medication
- Desmopressin (dDAVP) and similar drugs — tolvaptan blocks the same receptor these drugs target, so they will not work properly if taken together
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Do not take tolvaptan if you have significant liver disease or a history of liver injury (not including uncomplicated polycystic liver disease)
- Do not take if you are dehydrated or have low blood volume (hypovolemia)
- Do not take if your blood sodium is too low or too high and has not been corrected
- Do not take if you cannot feel or respond to thirst
- Do not take if you have a blocked urinary tract or produce no urine at all
- Do not take with strong CYP3A inhibitors
- Tell your doctor if you are pregnant — animal studies suggest possible risk to a developing baby, and this drug should be used in pregnancy only if clearly needed after careful discussion
- Breastfeeding is not recommended while taking this medication
- Tell your doctor about all medications, supplements, and herbal products you take — especially anything that affects the liver or CYP3A enzymes
🚑If you take too much▾
Taking too much tolvaptan would be expected to cause an extreme version of its normal effects: very high sodium levels in the blood, heavy urination, intense thirst, and dehydration. There is no specific antidote. If an overdose is suspected, medical evaluation is recommended — including checking vital signs, sodium and electrolyte levels, heart rhythm (ECG), and fluid status, with water and electrolyte replacement as needed. Dialysis is unlikely to help because tolvaptan binds very tightly to proteins in the blood.
📡Pharmacodynamics — effects in the body▾
Tolvaptan starts increasing urine output within 1 to 2 hours of a dose. The peak effect on urine production occurs roughly 4 to 8 hours after taking it, and urine output returns toward normal within 24 hours of the last dose. Because the drug causes the kidneys to release more free water, blood sodium levels tend to rise unless you drink enough fluids to replace what you're losing. With the recommended twice-daily dosing schedule, the drug effectively blocks the vasopressin signal in the kidney throughout the entire day, keeping urine output elevated and urine concentration low.
🔬Pharmacokinetics — how your body processes it▾
After an oral dose, tolvaptan reaches peak blood levels within about 2 to 4 hours. It can be taken with or without food, though a high-fat meal can roughly double the peak concentration (though not the total amount absorbed over time). Tolvaptan binds very strongly to proteins in the blood (over 98%), and it is primarily broken down by the liver enzyme CYP3A. Its breakdown products have little to no activity at the V2 receptor compared to tolvaptan itself.
📦How to store it▾
Store at 20°C to 25°C (68°F to 77°F), excursions permitted between 15°C and 30°C (59°F to 86°F) .
📄 Written from Tolvaptan (low blood sodium)’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Tolvaptan (low blood sodium) — the kind of thing our pharmacy team would talk through with you at the counter.
Why do I need to go to a special pharmacy to get this medication? ▾
I'm going to the bathroom constantly — is that normal? ▾
What liver symptoms should I watch out for? ▾
Can I take my other medications alongside tolvaptan? ▾
Is it safe to take this medication if I'm pregnant or trying to get pregnant? ▾
What happens if I miss a dose? ▾
Is Tolvaptan (low blood sodium) available over the counter? ▾
💬 Answers drafted from Tolvaptan (low blood sodium)’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
📈 How widely Tolvaptan (low blood sodium) is used
A general measure of how commonly Tolvaptan (low blood sodium) is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Tolvaptan (low blood sodium) is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Tolvaptan (low blood sodium) prescribed? Of the 1,597 medications we measure, Tolvaptan (low blood sodium) ranks #1,027 by Medicaid prescriptions — more than 36% of them.
Utilization by Tolvaptan (low blood sodium) product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
Hyponatremia tolvaptan 15 MG Oral Tablet Most dispensed
Summed across the 3 of 17 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 849827
Hyponatremia tolvaptan 30 MG Oral Tablet
Summed across the 1 of 17 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 849833
Other Tolvaptan (low blood sodium) products — combination packs and listings not yet matched to a specific clinical product (kept visible so every prescription is accounted for)
Summed across the 9 of 20 listed NDC products with Medicaid activity.
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Tolvaptan (low blood sodium), and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 13 of 54 listed Tolvaptan (low blood sodium) NDCs with Medicaid activity.
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Tolvaptan (low blood sodium) — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Tolvaptan (low blood sodium) in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Tolvaptan (low blood sodium) went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 358257 1 dose form · 7 strengths
-
Dose form (SCDF) Oral Tablet RxCUI 849826No current FDA listingClinical drug / strength (SCD) Hyponatremia tolvaptan 15 MGRxCUI 849827Hyponatremia tolvaptan 30 MGRxCUI 84983315 MGRxCUI 271933530 MGRxCUI 271933745 MGRxCUI 204435960 MGRxCUI 204436390 MGRxCUI 2044367
Look up RxCUI 358257 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Tolvaptan (low blood sodium) is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
RxNorm drug class
Tolvaptan (low blood sodium) belongs to the Vasopressin V2 Receptor Antagonist class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Otsuka America Pharmaceutical, Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.