Tenapanor

IBSRELA

Open Tenapanor in the interactive console ↗

Pronunciation: ten-A-pa-nor (ibs-REL-a)

Tenapanor ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Tenapanor ballicule

What it isNHE3 inhibitor reducing intestinal sodium and phosphate absorption; IBS with constipation and hyperphosphatemia in dialysis.

Why this oneIt reduces phosphate absorption rather than binding it, so it is not a binder and the pill burden is small.

What limits itDiarrhea is common and dose-limiting; contraindicated in mechanical GI obstruction.

Pearls

Take just before breakfast and dinner
IBS-C: modest benefit after fiber and PEG fail, like linaclotide

Tenapanor molecular structure (skeletal formula) — Molecular structure: Tenapanor

Tenapanor prescription history

Animated chart of estimated U.S. prescriptions per year, Constipation meds (1900–2026). Tenapanor enters in 2019 (estimated).

FDA-approved for

IBS with constipation (2019)
hyperphosphatemia in dialysis (2023)

Classes and tags

Clinical profile

Therapeutic safety burden1 / 4

Overdose danger1 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk0 / 4

Legacy pregnancy categoryNot assigned — PLLR-era drug

Defining liabilityDiarrhea, dehydration and electrolyte disturbance, especially with excessive or prolonged use.

FDA label

Read the full label on DailyMed ↗

BOXED WARNING Risk of serious dehydration in pediatric patients: contraindicated <6 years; avoid 6 to <12 years; safety/effectiveness not established <18 years

FDA dosing	Population	Start	Target	Max
Irritable bowel syndrome with constipation (IBS-C)	Adults	50 mg BID	50 mg BID	50 mg BID

Renal No dose adjustment stated; ESRD on HD (eGFR <15): M1 exposure not notably different; diarrhea more frequent with renal impairment (20% vs 13%)

Hepatic No dose adjustment stated; moderate (Child-Pugh B): M1 exposure lower, not clinically relevant

OATP2B1 substrates (e.g., enalapril): reduced exposure — monitor efficacy/BP and adjust that drug

Instructions

Take immediately before breakfast (or first meal of the day) and immediately before dinner
Missed dose: skip it and take the next dose at the regular time; do not take 2 doses at once
Severe diarrhea: suspend dosing and rehydrate

Available strengths

tab 20, 30, 50 mg

Contraindications

Patients less than 6 years of age (risk of serious dehydration)
Known or suspected mechanical gastrointestinal obstruction

Cautions

Risk of serious dehydration in pediatric patients (contraindicated <6 yr; avoid 6 to <12 yr)
Diarrhea — severe in 2.5%; suspend dosing and rehydrate

Adverse reactions

Diarrhea (16% vs 4% placebo)
Abdominal distension (3%)
Flatulence (3%)
Dizziness (2%)

Pregnancy Minimally absorbed; maternal use not expected to cause fetal exposure; limited human data show no drug-associated risk

Lactation Tenapanor and M1 not detected in human breast milk; infant exposure not expected

Cost

Tenapanor (IBSRELA)

Strength		#/mo	CostPlus
20 mg	tab	60 BID	not offered
30 mg	tab	60 BID	not offered
50 mg	tab	60 BID	not offered

NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Tenapanor is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.

Generic entry2034 est.

Open Tenapanor in the interactive console ↗

Self-check

Is tenapanor a phosphate binder?
No; it reduces phosphate absorption.
Below what age is tenapanor contraindicated?
Under 6 years.