Dosing & Uses
Dosage Forms & Strengths
tablet
- 10mg (Xphozah)
- 20mg (Xphozah)
- 30mg (Xphozah)
- 50mg (Ibsrela)
Irritable Bowel Syndrome with Constipation
Indicated for irritable bowel syndrome with constipation (IBS-C) in adults
50 mg PO BID immediately before breakfast and dinner
Serum Phosphorus Reduction
Indicated to reduce serum phosphorus in adults with chronic kidney disease (CKD) on dialysis as add-on therapy in those who have an inadequate response to phosphate binders or who are intolerant of any dose of phosphate binder therapy
30 mg PO BID immediately before breakfast and dinner
Monitor serum phosphorus and adjust dosage as needed to manage gastrointestinal tolerability
Dosage Modifications
Renal or hepatic impairment: No dose adjustments required
Irritable Bowel Syndrome with Constipation
<18 years: Safety and efficacy not established
Also see Black Box Warning and Contraindications
Pediatric Hyperphosphatemia (Orphan)
Orphan designation for treatment of pediatric hyperphosphatemia
Orphan sponsor
- Ardelyx, Inc; 400 Fifth Ave, Suite 210; Waltham, MA 02451
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (0)
Monitor Closely (10)
- atorvastatin
tenapanor decreases levels of atorvastatin by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- bosentan
tenapanor decreases levels of bosentan by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- conjugated estrogens
tenapanor decreases levels of conjugated estrogens by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- enalapril
tenapanor decreases levels of enalapril by Other (see comment). Modify Therapy/Monitor Closely. Comment: Tenapanor inhibits intestinal uptake transporter, OATP2B1; peak exposure (Cmax) of enalapril and its active metabolite, enalaprilat, decreases significantly when both drugs administered concomitantly; monitor blood pressure and increase dosage of enalapril, if needed, when coadministered with this drug.
- fexofenadine
tenapanor decreases levels of fexofenadine by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- fluvastatin
tenapanor decreases levels of fluvastatin by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- glyburide
tenapanor decreases levels of glyburide by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- pravastatin
tenapanor decreases levels of pravastatin by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- rosuvastatin
tenapanor decreases levels of rosuvastatin by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- sodium polystyrene sulfonate
sodium polystyrene sulfonate will decrease the level or effect of tenapanor by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate administration by at least 3 hours
Minor (0)
Adverse Effects
>10%
IBS-C
- Diarrhea (15-16%)
CKD
- Diarrhea (43-53%)
1-10%
IBS-C
- Abdominal distension (2-3%)
- Flatulence (3%)
- Severe diarrhea (2.5%)
- Dizziness (2%)
- Rectal bleeding (<2%)
- Abnormal GI sounds (<2%)
CKD
- Severe diarrhea (5%)
Warnings
Black Box Warnings
Risk of serious dehydration in pediatric patients
Contraindicated in patients aged <6 years
Studies in young juvenile rats administered tenapanor reported deaths related to dehydration
Avoid use in patients aged 6 to <12 yr
Safety and effectiveness not established in patients aged <18 yr
Contraindications
Children aged <6 years owing to risk of serious dehydration
Known or suspected mechanical GI obstruction
Cautions
Diarrhea may occur; if severe, suspend dosing and rehydrate patient
Contraindicated in children aged <6 yr; avoid use in children aged 6-12 yr owing to risk of dehydration in young children
Drug interaction overview
- Inhibitor of intestinal uptake transporter, OATP2B1
-
OATP2B1 substrates
- Monitor for signs related to loss of efficacy and adjust OATP2B1 substrate dose accordingly
- Tenapanor may reduce systemic exposure of OATP2B1 substrates
- When enalapril was coadministered with tenapanor (30 mg PO BID for 5 days, a dosage 0.6x the recommended dosage), peak exposure of enalapril and its active metabolite, enalaprilat, decreased by ~70% and total systemic AUC decreased by ~50- 65% compared to when enalapril was administered alone
- Monitor blood pressure and increase dosage of enalapril, if needed
-
Sodium polystyrene sulfate
- Modify dosage regimen
- Separate administration of tenapanor and sodium polystyrene sulfonate (SPS) by at least 3 hr
- SPS binds to tenapanor in gut
Pregnancy & Lactation
Pregnancy
Tenapanor is minimally absorbed systemically, with plasma concentrations below the limit of quantification
Maternal use is not expected to result in fetal drug exposure
Lactation
Data are not available regarding the presence in either human or animal milk, its effects on milk production, or its effects on the breastfed infant
The minimal systemic absorption of tenapanor will not result in a clinically relevant exposure to breastfed infants
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Tenapanor is a locally acting inhibitor of the sodium/hydrogen exchanger 3 (NHE3), an antiporter, also known as a countertransporter, on the apical surface of the small intestine and colon primarily responsible for absorption of dietary sodium
In vitro and animal studies indicate its major metabolite, M1, is not active against NHE3
NHE3 inhibition reduces sodium absorption from the small intestine and colon, resulting in an increase in water secretion into the intestinal lumen, which accelerates intestinal transit time and results in a softer stool consistency
Inhibition of NHE3 also results in decreased phosphate absorption by reducing phosphate permeability through the paracellular pathway
May decrease abdominal pain by decreasing visceral hypersensitivity; shown to reduce visceral hyperalgesia and to normalize colonic neural excitability in animal models
Absorption
Minimally absorbed following repeated BID PO administration; plasma concentrations were below the limit of quantitation (<0.5 ng/mL)
Peak plasma concentration (M1 metabolite): ~13 ng/mL after single 50-mg dose; 15 ng/mL (steady-state)
Effect of food
- Administration of tenapanor 5-10 minutes before a meal increased 24-hr stool sodium and phosphorus excretion compared with taking tenapanor in the fed or fasting condition
Distribution
Protein bound: 99%; 97% (M1 metabolite)
Metabolism
Metabolized primarily by CYP3A4/5, and low levels of its major metabolite, M1, are detected in plasma
Elimination
Excretion: 70% (feces); 9% (urine)
Administration
Oral Administration
Take immediately before breakfast or the first meal of the day and immediately before dinner
Missed dose
- Skip missed dose and take the next dose at the regular time
- Do not take 2 doses at the same time
Hemodialysis
- Do not administer right before a hemodialysis session
- Instead, take right before the next meal following dialysis, as patients may experience diarrhea after taking tenapanor
Storage
Store at 68-77ºF (20-25ºC); excursion permitted to 15-30C (59-86F)
Keep in tightly closed original container and protect from moisture
Do not remove desiccant from the bottle
Do not subdivide or repackage
Images
Formulary
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