Overview
Tenapanor is the newest FDA-approved drug for IBS with constipation (IBS-C). This study seeks to understand tenapanor as a treatment for cystic fibrosis-related constipation (CFrC) in CF patients. Participants will ingest one 50 mg tablet of tenapanor, twice daily, for a 4-week treatment period. They will also complete three questionnaires, the PAC-SYM, PAC-QoL, and IBS-SSS, and daily diaries to characterize GI symptom burden and spontaneous bowel movement (SBM) frequency.
Eligibility
Inclusion Criteria:
- Having confirmed cystic fibrosis (either by sweat chloride or genetic testing)
- Meeting criteria for CFrC
Must include 2 of the following, with or without abdominal pain for at least 3 months, with symptom onset at least 6-months prior:
- Straining in at least 25% of defecations
- Bristol Stool Scale 1-2 more than 25% of defecations (change in stool form)
- Sensation of incomplete evacuation more than 25% of defecations
- Sensation of anorectal obstruction/blockage more than 25% of defecations
- Manual disimpaction/manipulation of pelvic floor to facilitate more than 25% of defecations
- Fewer than 3 spontaneous bowel movements weekly (change in stool frequency)
- Loose stools rarely present without the use of laxatives
- Willingness to avoid major dietary or lifestyle changes during study.
Exclusion Criteria:
- Use of any antibiotic to treat infection within the 4-weeks prior to study initiation (stable azithromycin dosed 3-times weekly for lung function is to be allowed)
- Inability to discontinue standing bowel regimen (including fiber, stool softener, as well as either osmotic or stimulant laxative, pro-kinetic serotonergic agents, or other therapy) 2-weeks prior to study drug initiation (with ability to use osmotic laxative therapy as rescue therapy only).
- Severe CFrC as determined by study team
- Prior tenapanor usage
- Hospitalization within 4-weeks prior to study initiation.
- DIOS within 4-weeks prior to study initiation.
- Other known/suspected mechanical obstruction