Tenapanor
Tenapanor is a gut-acting tablet used to treat irritable bowel syndrome with constipation (IBS-C) in adults and to lower high phosphorus levels in adults with chronic kidney disease on dialysis.
🧬 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 2 clinical label sets 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 ▾
Important safety warning for children: Ibsrela (tenapanor) must not be given to children under 6 years old. In animal studies, young animals given tenapanor died, likely from severe dehydration caused by diarrhea. Use in children ages 6 to under 12 should also be avoided. Tenapanor has not been shown to be safe or effective in anyone under 18 years of age. If a child accidentally takes this medication, seek emergency medical help immediately.
📖 Tenapanor: Patient Information Guide
A plain-language walkthrough of Tenapanor — 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▾
Tenapanor is the active ingredient in two separate branded products approved for different conditions:
- Ibsrela (tenapanor tablet) — treats irritable bowel syndrome with constipation (IBS-C) in adults
- XPHOZAH (tenapanor tablet, film coated) — reduces high serum phosphorus in adults with chronic kidney disease (CKD) who are on dialysis, used as an add-on when phosphate binder therapy has not produced an adequate response or is not tolerated at any dose
⚙️How it works▾
Tenapanor blocks a protein called NHE3 (sodium/hydrogen exchanger 3) that sits on the inner surface of the small intestine and colon. NHE3 normally absorbs sodium — and pulls water along with it — from the gut into the body. By blocking NHE3, tenapanor keeps more water inside the intestine, softening stool and speeding up bowel movement. In IBS-C, it also reduces abdominal pain by calming oversensitive gut nerves and decreasing intestinal permeability (leakiness). In CKD, blocking NHE3 reduces how much phosphorus the gut absorbs, helping to lower phosphorus levels in the blood.
Tenapanor is minimally absorbed into the bloodstream — it works almost entirely inside the gut — which means its effects are mainly local.
💊How it's taken▾
Tenapanor tablets are taken twice daily by mouth, before meals. Timing before meals matters — taking it just before eating increases its effectiveness.
- Ibsrela: take immediately before breakfast (or your first meal) and immediately before dinner. Skip any missed dose; do not take two at once.
- XPHOZAH: take just before the first and last meals of the day. If you are on hemodialysis, do not take your dose right before your dialysis session — take it before your next meal after dialysis. Skip any missed dose and resume your regular schedule.
🤒Side effects — in detail▾
The most commonly reported side effects with tenapanor include:
- Diarrhea (most frequent — reported in about 1 in 6 Ibsrela-treated patients in trials)
- Abdominal bloating (distension)
- Gas (flatulence)
- Dizziness
Severe diarrhea occurred in about 2.5% of Ibsrela-treated patients in clinical trials. If diarrhea becomes severe, stop taking the medication, drink plenty of fluids to stay hydrated, and contact your doctor right away — prolonged diarrhea can cause dangerous dehydration.
⚠️Warnings & precautions▾
- Serious dehydration in children: Tenapanor must not be given to children under 6 — animal studies showed deaths from dehydration. Use in children 6 to under 12 should also be avoided. Safety and effectiveness have not been established in anyone under 18.
- Severe diarrhea: This is the most common serious risk in adults. If you experience severe diarrhea, stop the medication and rehydrate. Seek medical care if it does not improve quickly.
- Bowel obstruction: XPHOZAH is contraindicated (must not be used) in anyone with a known or suspected mechanical blockage in the digestive tract.
🔀What it interacts with▾
Tenapanor can affect how certain other medications are absorbed in the gut. Key interactions to know:
- OATP2B1 substrate drugs (e.g., enalapril): Tenapanor inhibits an intestinal transporter called OATP2B1, which can significantly reduce the absorption of drugs that rely on it. Enalapril levels dropped by roughly 50–70% in studies with XPHOZAH. Monitor for reduced effectiveness of these medications.
- Sodium polystyrene sulfonate (SPS): Separate XPHOZAH and SPS by at least 3 hours — SPS can bind to many oral drugs and reduce their absorption.
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▾
- Children under 6: Contraindicated — serious risk of dehydration and death
- Children 6 to under 12: Avoid use of Ibsrela; safety not established
- Anyone under 18: Safety and effectiveness not established for either product
- Bowel blockage: XPHOZAH is contraindicated in patients with known or suspected mechanical gastrointestinal obstruction
- Pregnancy: Tenapanor is minimally absorbed systemically, so fetal exposure is not expected; discuss with your doctor
- Breastfeeding: Tenapanor and its major metabolite were not detected in breast milk; discuss benefits and risks with your provider
- Liver impairment: Moderate liver impairment reduced levels of the metabolite M1, but this is not considered clinically significant
- Taking enalapril or SPS: Tell your doctor before starting tenapanor
🚑If you take too much▾
There is no specific overdose data in patients. Based on how tenapanor works, taking too much would likely cause gastrointestinal effects — especially diarrhea — which could lead to significant dehydration if severe or prolonged. If you suspect an overdose, seek medical attention right away and stay well hydrated.
📡Pharmacodynamics — effects in the body▾
Tenapanor's main measurable effect is in the gut: it increases water secretion into the intestinal lumen (the inside of the bowel), softens stool, and speeds up intestinal transit. For XPHOZAH, it increases phosphorus excretion in stool by reducing gut absorption of phosphorus. Taking tenapanor 5–10 minutes before a meal produces the greatest effect on stool sodium or phosphorus excretion compared to taking it while eating or fasting. At recommended doses, tenapanor does not have a meaningful effect on heart rhythm (QTc interval).
🔬Pharmacokinetics — how your body processes it▾
Tenapanor is barely absorbed into the bloodstream after oral dosing — blood levels are below detectable limits in most people, which is why it acts locally in the gut rather than throughout the body. It is processed primarily by liver enzymes (CYP3A4/5), and most of the drug leaves the body through the stool (about 70–79% within five to ten days), largely unchanged. A small amount exits via urine as metabolites. Its minimal systemic absorption means that liver or kidney impairment does not meaningfully change how the body handles the drug overall.
📦How to store it▾
Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F) . protect from moisture. Store and dispense in original bottle with the desiccant.
📄 Written from Tenapanor’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 →
Supplements & herbs that interact with Tenapanor
138 supplements and herbal products have documented interactions with Tenapanor in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 3
- Moderate · 94
- Minor · 41
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Tenapanor — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is tenapanor used for? ▾
Why do I need to take it right before eating — does timing really matter? ▾
What side effects should I expect, and when should I actually call my doctor? ▾
Is this medication safe if I'm pregnant or breastfeeding? ▾
Can I give this to my child if they have the same problem? ▾
Does tenapanor interact with any of my other medications? ▾
Is Tenapanor available over the counter? ▾
When was Tenapanor first available? ▾
Who makes Tenapanor? ▾
💬 Answers drafted from Tenapanor’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 Tenapanor comes
Tenapanor is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Ibsrela is used to treat irritable bowel syndrome with constipation (IBS-C) in adults
- XPHOZAH is used to reduce high phosphorus levels in adults with chronic kidney disease on dialysis, when phosphate binders have not worked well enough or are not tolerated
- Ibsrela: take immediately before breakfast or your first meal of the day, and immediately before dinner; if you miss a dose, skip it and take the next one at the regular time — do not take two doses at once
- XPHOZAH: take just before the first and last meals of the day; do not take right before a hemodialysis session — instead, take it before the next meal after dialysis
- XPHOZAH: if you miss a dose, skip it and take your next dose at the regular time
Show 1 more strength Show fewer strengths
📊 Tenapanor across the U.S. market
How Tenapanor appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (4) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Tenapanor is used
A general measure of how commonly Tenapanor 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 Tenapanor 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 Tenapanor prescribed? Of the 1,597 medications we measure, Tenapanor ranks #658 by Medicaid prescriptions — more than 59% of them.
Utilization by Tenapanor 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.
tenapanor 50 MG Oral Tablet Most dispensed
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2199679
tenapanor 30 MG Oral Tablet
Summed across the 1 of 3 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2669452
tenapanor 20 MG Oral Tablet
Summed across the 1 of 3 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2669448
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 Tenapanor, 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 3 of 8 listed Tenapanor NDCs with Medicaid activity.
🔍 Compare Tenapanor products
A representative set of FDA-listed product records for Tenapanor — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 10 mg | Oral | Ardelyx, Inc. | NDA | View NDC → |
| 10.6 mg | Oral | Ardelyx, Inc. | NDA | View NDC → |
| 20 mg | Oral | Ardelyx, Inc. | NDA | View NDC → |
| 21.3 mg | Oral | Ardelyx, Inc. | NDA | View NDC → |
| 30 mg | Oral | Ardelyx, Inc. | NDA | View NDC → |
| 31.9 mg | Oral | Ardelyx, Inc. | NDA | View NDC → |
| 53.2 mg | Oral | Ardelyx, Inc. × 2 listings | NDA | View NDC → |
| 10 mg | — | Patheon Pharmaceuticals Inc. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 21.3 mg | — | Patheon Pharmaceuticals Inc. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 31.9 mg | — | Patheon Pharmaceuticals Inc. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 53.2 mg | — | Patheon Pharmaceuticals Inc. | DRUG FOR FURTHER PROCESSING | View NDC → |
| 💊Bulk drug substance | ||||
| 1 kg/kg | — | Chunghwa Chemical Synthesis & Biotech Co., Ltd. | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Hovione FarmaCiencia SA | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Valdepharm × 2 listings | BULK INGREDIENT | View NDC → |
Showing 16 of 16 products — FDA National Drug Code Directory. See every product, package size and price: browse all 16 Tenapanor NDCs →
📈 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 Tenapanor — 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 Tenapanor 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 Tenapanor 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 2199674 1 dose form · 4 strengths
-
Dose form (SCDF) Oral Tablet RxCUI 2199678In current FDA listings
Look up RxCUI 2199674 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 Tenapanor 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
🏭 Manufacturers & labelers
RxNorm drug class
Tenapanor belongs to the Sodium-Hydrogen Exchanger 3 Inhibitor 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 2 FDA-filed SPL label sets 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. Ardelyx, 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.