General

Pronunciation:
ten-a-pa-nor

Trade Name(s)

• Ibsrela
• Xphozah

Ther. Class.

anti irritable bowel syndrome agents

electrolyte modifiers

Pharm. Class.

phosphate binders

sodium hydrogen exchanger 3 inhibitors

Indications

• Ibsrela: Irritable bowel syndrome with constipation (IBS-C).
• Xphozah: Patients with chronic kidney disease on dialysis who have an inadequate response to phosphate binders or are intolerant of any dose of phosphate binder therapy.

Action

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 Effect(s):

• 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 and 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)

Contraindication/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.

Adverse Reactions/Side Effects

GU: diarrhea, abdominal distension, flatulence

Neuro: dizziness

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

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.

Evaluation/Desired Outcomes

• Increased frequency of bowel movements with decreased pain associated with IBS-C.
• Decreased serum phosphorus concentrations in patients with chronic kidney disease on dialysis.