Tenapanor

IBSRELA

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 dose-limiting and is the mechanism. Contraindicated under age 6.

FDA-approved for

FDA dosing	Population	Start	Target	Max
Hyperphosphatemia in CKD on dialysis (add-on/intolerant to binders)	Adults	30 mg BID	30 mg BID	30 mg BID

Renal Undefined

Hepatic Undefined

Take orally BID just before the morning and evening meals
Do not take right before a hemodialysis session — take before the next meal after dialysis
Adjust dose to manage GI tolerability; skip missed dose

Pediatric patients under 6 years of age (risk of diarrhea and serious dehydration)
Known or suspected mechanical GI obstruction

Severe diarrhea (up to 53% of patients; may cause dehydration and hyponatremia) — discontinue if severe

Pregnancy Essentially non-absorbed; maternal use not expected to result in fetal exposure; available data show no drug-associated risk

Lactation Not detected in human milk; maternal use not expected to expose infant

⚠ BOXED WARNING

Cost, est. cash$300–$2,500/month

Generic entry2034 est.

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.