Tenapanor for Irritable Bowel Syndrome with Constipation (IBS-C)
Clinical Guideline Support and Efficacy Data
- The American Gastroenterological Association (AGA) suggests using tenapanor in patients with IBS-C (conditional recommendation, moderate certainty of evidence) 1, 2, 3
- 34.1% of tenapanor-treated patients met the FDA responder endpoint versus 21.7% with placebo (FDA endpoint = 30% reduction in abdominal pain + 1 additional complete spontaneous bowel movement per week for 6 of 12 weeks) 3
- Tenapanor improved abdominal pain response with a risk difference of 12.1% over placebo 3
- Complete spontaneous bowel movement (CSBM) response improved with a risk difference of 11.3% over placebo 3
- In phase 3 trials, 58.1% of tenapanor patients reported adequate relief of IBS symptoms at 12 weeks versus 41.1% with placebo 3
Safety Profile and Adverse Effects
- Diarrhea is the most common adverse effect, occurring in approximately 16% of patients versus 4% with placebo 3
- Diarrhea led to treatment discontinuation in 6.6% of tenapanor patients versus 1.0% with placebo 3
Mechanism of Action and Drug Interactions
- Tenapanor is a first-in-class, minimally absorbed, selective inhibitor of intestinal sodium/hydrogen exchanger isoform 3 (NHE3) 3
- Monitor OATP2B1 substrates (e.g., enalapril) for potential reduced exposure when co-administered with tenapanor 3
- Monitor for signs related to loss of efficacy of the concomitant drug and adjust dosage of concomitantly administered drug as needed 3