Xphozah

Generic name: tenapanor
Dosage form: tablet (10mg, 20mg, 30mg)
Drug class: NHE3 inhibitors

Medically reviewed by Melisa Puckey, BPharm. Last updated on Feb 8, 2024.

What is Xphozah?

Xphozah is a phosphate absorption inhibitor that is used to lower serum phosphorus levels for patients with chronic kidney disease (CKD) on dialysis who have tried phosphate binders but they have not worked well enough, or they are unable to take them. Xphozah is a twice a daily tablet that works by blocking phosphate absorption in the gut to help return phosphate to normal serum levels. Xphozah is the first and only phosphate absorption inhibitor that has been approved by the Food and Drug Administration (FDA).

Xphozah (tenapanor) became an FDA-approved medication on Oct. 17, 2023, after positive results from three Phase 3 clinical trials (PHREEDOM, BLOCK, and AMPLIFY) showing Xphozah significantly reduced high serum phosphorus in patients receiving maintenance hemodialysis. Xphozah is FDA-approved to reduce serum phosphorus in adults with chronic kidney disease (CKD) on dialysis as add-on therapy in patients who have an inadequate response to phosphate binders or are intolerant of any dose of phosphate binder therapy.

Results from the three clinical trials showed that Xphozah significantly reduced elevated serum phosphorus in patients who were on maintenance hemodialysis.

What is hyperphosphatemia?

Hyperphosphatemia is when you have high or too much phosphorus in your blood. One of the kidneys' jobs is to filter out and remove excess phosphorus, but if you have kidney disease, your kidneys may not remove extra phosphorus, which leads to high phosphorus levels. High serum phosphorus levels are a common condition among people with chronic kidney disease (CKD) on maintenance dialysis. Treatment for high serum phosphorus levels is often with dietary restriction and phosphate binder therapy, but for those who do not get an adequate response or who are intolerant of phosphate binder therapy, Xphozah can be used as an add-on therapy or stand-alone therapy. Phosphate binders act by binding dietary phosphate to form insoluble complexes that pass through the GI tract without being absorbed.

How does Xphozah work?

Xphozah is a phosphate absorption inhibitor, which means it reduces how much phosphate is absorbed from the gut into the bloodstream, this results in lower serum phosphorus levels. Xphozah works to reduce phosphate absorption by inhibiting the sodium hydrogen exchanger 3 (NHE3) in the gastrointestinal tract. Blocking NHE3 reduces phosphate absorption through the paracellular pathway, which is the main pathway that phosphorus is absorbed.

Xphozah side effects

The most common Xphozah side effect was diarrhea which affected 43-53% of patients with CKD in clinical trials. Most of the diarrhea events were reported to be mild-to-moderate in severity and did resolve over time or with dose reduction. Diarrhea was usually reported soon after starting treatment but could occur at any time during treatement. Severe diarrhea was reported in 5% of Xphozah-treated patients in these trials.

Warning

Diarrhea. Patients using Xphozah may experience severe diarrhea. Treatment with this medicine should be discontinued in patients who develop severe diarrhea. Do NOT not to use stool softeners or laxatives with Xphozah.

Who should not take Xphozah?

You should not take Xphozah if:

you have known or suspected mechanical gastrointestinal obstruction.

How to take Xphozah

Take tablets just before the first and last meals of the day.

Do not take Xphozah right before a hemodialysis session; instead, take it right before the next meal following dialysis, as some patients may experience diarrhea after taking It.

Dosing information

Usual adult Xphozah dose is a single tablet taken twice daily.

The recommended dosage is 30 mg orally twice daily. Monitor serum phosphorus levels and adjust the dosage as needed to manage gastrointestinal tolerability.

Xphozah is available in 10mg, 20mg, and 30mg tablets.

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.

Xphozah is indicated for adult use.

Interactions

Tell your doctor about all your current medicines and any you start or stop using, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

The active ingredient of Xphozah is Tenapanor which is an inhibitor of intestinal uptake transporter, OATP2B1. There is potential for reduced exposure to 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.