Tenapanor: uses, dosing, side effects & brands
Tenapanor is a medicine sold in the U.S. under one brand, for irritable bowel syndrome. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Treats
- Irritable Bowel Syndrome
- Available as
- Tablet
- Sold as
- Ibsrela
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- Boxed warning
- Boxed warning
How tenapanor is dosed
From the FDA label for Ibsrela (application NDA211801). Other tenapanor products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
The recommended dosage of IBSRELA in adults is 50 mg orally twice daily. The recommended dosage in adults is 50 mg, orally twice daily. ( 2 ) Take immediately prior to breakfast or the first meal of the day and immediately prior to dinner. ( 2 ) Administration Instructions Take IBSRELA immediately prior to breakfast or the first meal of the day and immediately prior to dinner [see Clinical Pharmacology (12.2) ] . If a dose is missed, skip the missed dose and take the next dose at the regular time. Do not take 2 doses at the same time.
Tenapanor side effects
Most common adverse reactions (≥2%) are diarrhea, abdominal distension, flatulence and dizziness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ardelyx at 1-844-427-7352 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. The safety data described below reflect data from 1203 adult patients with IBS-C in two randomized, double-blind, placebo-controlled clinical trials (Trial 1 and Trial 2). Patients were randomized to receive placebo or IBSRELA 50 mg twice daily for up to 52 weeks. Demographic characteristics were comparable between treatment groups in the two trials [see Clinical Studies (14) ] . Most Common Adverse Reactions The most common adverse reactions reported in at least 2% of patients in IBSRELA-treated patients and at an incidence greater than placebo during the 26-week double-blind placebo-controlled treatment period of Trial 1 are shown in Table 1. Table 1: Most Common Adverse Reactions Reported in at least 2% of patients in IBSRELA-treated patients and at an incidence greater than placebo in Patients with IBS-C in Trial 1 (26 Weeks) Adverse Reactions IBSRELA N=293…
Who shouldn’t take tenapanor
IBSRELA is contraindicated in: Patients less than 6 years of age due to the risk of serious dehydration [see Warnings and Precautions (5.1) , Use in Specific Populations (8.4) ]. Patients with known or suspected mechanical gastrointestinal obstruction . Pediatric patients less than 6 years of age. ( 4 , 5.1 , 8.4 ) Patients with known or suspected mechanical gastrointestinal obstruction. ( 4 )
Tenapanor drug interactions
OATP2B1 Substrates: Potential for reduced exposure of the concomitant drug (e.g., enalapril). Monitor for signs related to loss of efficacy and adjust the dosage of the concomitantly administered drug as needed. ( 7.1 ) 7.1 OATP2B1 Substrates Tenapanor is an inhibitor of intestinal uptake transporter, OATP2B1 [see Clinical Pharmacology (12.3) ] . Drugs which are substrates of OATP2B1 may have reduced exposures when concomitantly taken with IBSRELA. Monitor for signs related to loss of efficacy and adjust the dosage of concomitantly administered drug as needed. Enalapril is a substrate of OATP2B1. When enalapril was coadministered with tenapanor (30 mg twice daily for five days, a dosage 0.6 times the recommended dosage), the peak exposure (C max ) of enalapril and its active metabolite, enalaprilat, decreased by approximately 70% and total systemic exposures (AUC) decreased by approximately 50% to 65% compared to when enalapril was administered alone [see Clinical Pharmacology (12.3) ] . Monitor blood pressure and increase the dosage of enalapril, if needed, when IBSRELA is coadministered with enalapril.
Every tenapanor product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Ibsrela.
What tenapanor pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| A50;5791 | 53.2 mg | white | oval | — |
What people report to the FDA about tenapanor
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 332 reports naming tenapanor, and the FDA flagged 96% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- diarrhoea83 reports
- hospitalisation21 reports
- cerebral infarction15 reports
- peritonitis13 reports
- cardiac failure11 reports
- fall10 reports
- shunt occlusion10 reports
- hyperkalaemia8 reports
Read these as a signal, not a rate. A report does not mean tenapanor caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 26, 2026.
Related calculators
Frequently asked questions
What is tenapanor?
IBSRELA (tenapanor) tablets contain tenapanor hydrochloride as an active ingredient. Tenapanor hydrochloride is a sodium/hydrogen exchanger 3 (NHE3) inhibitor for oral use.
Can you take tenapanor with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run tenapanor against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does tenapanor come in?
Across the brands we track, tenapanor is currently marketed as tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic tenapanor?
We do not currently list a generic-labelled tenapanor product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Tenapanor: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/tenapanor
- MLA
- “Tenapanor: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/tenapanor.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for tenapanor on DailyMed (NIH) ↗ — including its boxed warning in full.