tenapanor

Inhibits the sodium/hydrogen exchanger 3, which results in a reduction in sodium and phosphate reabsorption from the small intestine and colon and an increase in water secretion into the intestinal lumen. The increased water secretion accelerates intestinal transit time and softens stool consistency.

Therapeutic effects:

Increased frequency of bowel movements with decreased pain associated with IBS-C.
Decreased serum phosphorus concentrations.

Pharmacokinetics ⬆ ⬇

Absorption: Minimally absorbed, action is primarily local.

Distribution: Stays within the GI tract with minimal distribution.

Protein Binding: 99%.

Metabolism/Excretion: Primarily metabolized in the liver via the CYP3A4 and CYP3A5 isoenzymes. Primarily excreted in the feces as unchanged drug; minimal excretion in urine.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(improvement in IBS-C symptoms)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	6–9 wk	1–4 wk

‡Following discontinuation.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Known/suspected mechanical GI obstruction;
Pedi: Children <6 yr (↑ risk of severe diarrhea and dehydration).

Use Cautiously in:

Lactation: Use while breastfeeding only if potential maternal benefit justifies potential risk to infant.

Adv. Reactions/Side Effects ⬆ ⬇

GU: diarrhea, abdominal distension, flatulence

Neuro: dizziness

Interactions ⬆ ⬇

Drug-drug:

May ↓ levels and effectiveness of OATP2B1 substrates, including enalapril.
Absorption may be ↓ by sodium polystyrene sulfonate; separate administration by ≥3 hr.

Route/Dosage ⬆ ⬇

Ibsrela

PO (Adults ): 50 mg twice daily.

Xphozah

PO (Adults ): 30 mg twice daily.

Availability ⬆ ⬇

Tablets (Ibsrela): 50 mg
Tablets (Xphozah): 20 mg; 30 mg

Assessment ⬆ ⬇

Assess for abdominal distension, presence of bowel sounds, and usual pattern of bowel function.
Assess color, consistency, and amount of stool produced. Discontinue treatment in patients who develop severe diarrhea.

Lab Test Considerations:

Xphozah: Monitor serum phosphate levels prior to and periodically during therapy.

Implementation ⬆ ⬇

PO: Administer immediately prior to breakfast or the first meal of the day and immediately prior to dinner. If a dose is missed, omit and administer the next dose at the regular time. Do not give Xphozah immediately before a hemodialysis session; instead, give before the next meal following the dialysis session.

Patient/Family Teaching ⬆ ⬇

Educate patient on reason for tenapanor and side effects. Instruct patient to take tenapanor as directed. If a dose is missed, omit and take next dose at regular time. Do not take two doses at same time. Instruct patient to not take Xphozah immediately before a hemodialysis session to minimize risk of having diarrhea during session; advise patient to take it before the next meal following the dialysis session. Do not share medication with others, even if they have similar symptoms; may be harmful. Advise patient to read Patient Information before starting and with each Rx refill in case of changes.
Explain need for continued medical follow-up to assess effectiveness; periodic lab tests will be needed.
Advise patient to promptly notify health care professional if severe diarrhea occurs.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications. Advise patient to not use laxatives or stool softeners without first consulting health care professional.
Instruct patient to store at room temperature in the original container and protect from moisture. Do not put in another container (repackage). Do not remove the desiccant from the bottle.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding. Maternal use is not expected to result in fetal exposure due to minimal systemic absorption.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇