Does Vonprazan (Vonoprazan) cause constipation?

Vonoprazan and Constipation

Based on current evidence, vonoprazan does not significantly increase the risk of constipation compared to proton pump inhibitors (PPIs) and may actually be associated with lower rates of diarrhea. 1

Safety Profile of Vonoprazan

• Vonoprazan is a potassium-competitive acid blocker (P-CAB) that has been shown to be generally well-tolerated with short-term and medium-term safety profiles comparable to PPIs 2
• The most common adverse events reported with vonoprazan include abdominal pain, constipation, diarrhea, nausea, and dyspepsia 3
• A systematic review and meta-analysis specifically examining adverse events of vonoprazan found no significant increase in the overall incidence of adverse effects compared to PPIs 1

Gastrointestinal Side Effects

• While constipation is listed among potential side effects, meta-analysis data shows no statistically significant difference in constipation rates between vonoprazan and PPIs 1
• Interestingly, vonoprazan treatment was associated with a statistically significant decrease in diarrhea or loose stools compared to PPIs (95% CI = 0.661-0.966, p = 0.021) 1
• Other gastrointestinal symptoms such as bloating, abdominal pain, and nausea showed no significant differences between vonoprazan and PPIs 1

Clinical Considerations

• In pre-approval clinical studies for acid-related disorders, mild to moderate adverse drug reactions (including constipation or diarrhea) occurred at frequencies of 8-17% 4
• A study of vonoprazan 10 mg daily in PPI-resistant GERD patients found that scores for constipation and diarrhea were unchanged during the treatment period 5
• When evaluating patients on vonoprazan who report constipation, clinicians should consider other common causes of constipation in patients with acid-related disorders, including:
  • Concurrent medications (antacids, anticholinergics, antidepressants) 2
  • Reduced physical activity 2
  • Inadequate fluid intake 2

Management Approach

• For patients experiencing constipation while on vonoprazan:
  • Discontinue any nonessential constipating medications 2
  • Encourage increased fluid intake and physical activity when appropriate 2
  • Consider added dietary fiber for patients with adequate fluid intake 2
  • If constipation persists, standard treatments such as bisacodyl or polyethylene glycol may be considered 2

Summary

• Current evidence does not suggest that vonoprazan causes constipation at rates higher than conventional PPIs 1
• Vonoprazan may actually be associated with lower rates of diarrhea compared to PPIs 1
• When prescribing vonoprazan, clinicians should monitor for all potential side effects, but constipation does not appear to be a specific concern that would limit its use in appropriate patients 4, 1