What is Viberzi (eluxadoline)?

What is Viberzi (Eluxadoline)?

Viberzi (eluxadoline) is an FDA-approved prescription medication for treating irritable bowel syndrome with diarrhea (IBS-D) in adults, functioning as a mixed μ- and κ-opioid receptor agonist and δ-opioid receptor antagonist that acts locally in the gastrointestinal tract. 1

Mechanism of Action

Eluxadoline is a minimally absorbed, locally-acting compound that works through a unique triple mechanism 2:

• μ-opioid receptor agonist: Reduces intestinal motility and provides visceral analgesia
• κ-opioid receptor agonist: Enhances analgesic effects
• δ-opioid receptor antagonist: Counteracts constipation typically caused by pure μ-opioid agonists

This mixed receptor profile was specifically designed to control diarrhea and reduce abdominal pain while minimizing constipation risk compared to traditional opioids 3, 4.

FDA-Approved Dosing

Standard dose: 100 mg twice daily with food 2, 1

Reduced dose (75 mg twice daily) is recommended for 2, 1:

• Patients unable to tolerate the 100 mg dose
• Mild to moderate hepatic impairment
• Concurrent use of OATP1B1 inhibitors
• Severe renal impairment or end-stage renal disease not yet on dialysis 5

Clinical Efficacy

Based on two large phase 3 trials with 1,617 patients, eluxadoline demonstrates moderate efficacy 2:

Primary outcomes at 12 weeks:

• 27.2% vs 16.7% achieved FDA composite endpoint (improvement in both abdominal pain and stool consistency) compared to placebo
• Absolute benefit: 108 fewer treatment failures per 1,000 patients

Secondary benefits 2:

• Improved stool consistency (RR 0.84)
• Reduced urgency (50% urgency-free days: RR 0.84)
• Enhanced quality of life (RR 0.84)
• Adequate symptom relief in 38.4% vs 29.2% with placebo

Important nuance: Eluxadoline shows stronger effects on diarrhea and stool consistency than on abdominal pain 2. Therefore, it is most appropriate for IBS-D patients with predominant and bothersome diarrhea rather than those with severe abdominal pain as the primary complaint.

Guideline Recommendations

The 2022 AGA guidelines provide a conditional recommendation (moderate certainty evidence) for using eluxadoline in IBS-D patients 2. The British Society of Gastroenterology (2021) similarly recommends eluxadoline as a second-line treatment for IBS-D in secondary care (weak recommendation, moderate quality evidence) 6.

Critical Safety Concerns and Absolute Contraindications

ABSOLUTE CONTRAINDICATIONS 1:

Do NOT prescribe eluxadoline if the patient:

• Lacks a gallbladder (post-cholecystectomy)
• Drinks >3 alcoholic beverages daily
• Has history of pancreatitis or pancreatic disease
• Has sphincter of Oddi dysfunction or biliary obstruction
• Has severe liver impairment
• Has chronic or severe constipation
• Has history of bowel obstruction

Serious Adverse Events

Pancreatitis 2:

• Occurred in 5 patients (3 more per 1,000 vs placebo)
• Most cases in patients without gallbladders
• Typically occurs within first week, sometimes after just 1-2 doses
• Has resulted in death in some post-cholecystectomy patients
• High certainty evidence for this risk

Sphincter of Oddi spasm 2:

• 8 cases in trials (5 more per 1,000 vs placebo)
• Predominantly in patients without gallbladders
• Can cause severe upper abdominal pain radiating to back/shoulder
• High certainty evidence for this risk

Warning signs requiring immediate discontinuation 1:

• New or worsening abdominal pain, especially upper right quadrant
• Pain radiating to back or shoulder
• Severe constipation

Common Adverse Events 2:

• Constipation (8%)
• Nausea (7%)
• Abdominal pain (7%)
• Discontinuation rate: 8% vs 4% with placebo

Controlled Substance Status

Viberzi is a Schedule IV controlled substance due to potential for abuse or dependence, though actual risk appears low 1, 7. Patients should store medication securely and never share with others.

Drug Interactions

Avoid concurrent use with 1:

• Alosetron (another IBS-D medication)
• Chronic loperamide use (may use occasionally for acute severe diarrhea, but stop if constipation develops)
• Anticholinergic medications
• Opioid pain medications

These combinations increase constipation risk significantly.

Special Populations

Elderly patients (≥65 years): Experience increased adverse events including serious complications 1. Use with heightened caution.

Pregnancy/Breastfeeding: Unknown safety profile; effects on fetus or breast milk not established 1.

Renal impairment: Use 75 mg dose for severe impairment or end-stage renal disease 5.

Clinical Positioning

Eluxadoline is best suited for 2:

• IBS-D patients with predominant diarrhea and urgency as primary complaints
• Patients who have failed first-line therapies (dietary modifications, antispasmodics, loperamide)
• Patients with intact gallbladders and no alcohol abuse history
• Secondary care settings where careful patient selection and monitoring are feasible 6

Eluxadoline is NOT ideal for:

• Patients with severe abdominal pain as the dominant symptom
• Post-cholecystectomy patients (absolute contraindication)
• Patients with significant alcohol consumption
• Those with multiple contraindications or high-risk features

The medication provides meaningful symptom improvement in approximately 1 in 10 patients treated, with sustained benefits observed through 26 weeks in responders 2, 8.