Refractory GERD-induced chronic cough and vonoprazan

Refractory gastroesophageal reflux disease (GERD)-induced chronic cough (GERC) refers to a persistent cough caused by acid reflux that does not respond adequately to standard treatment with proton-pump inhibitors (PPIs). Chronic cough associated with GERD can significantly impact a patient’s quality of life, and finding effective treatment options for refractory cases is a clinical challenge.

### Key Points about Refractory GERD-Induced Chronic Cough and Vonoprazan:

#### 1. **Refractory GERD-Induced Chronic Cough:**

• **Definition:** Chronic cough lasting more than 8 weeks, attributed to GERD, that does not improve with standard PPI therapy.
• **Pathophysiology:** GERD-induced cough may occur due to microaspiration of stomach contents into the airways or a vagally mediated reflex triggered by esophageal acid exposure.
• **Challenges with PPIs:**
• PPIs work by inhibiting the proton pump in gastric parietal cells, reducing stomach acid production.
• Some patients experience incomplete acid suppression with PPIs, leading to persistent symptoms, including chronic cough.
• Variability in PPI response could be due to differences in metabolism, adherence, or acid breakthrough.

#### 2. **Vonoprazan as a New Treatment Option:**

• **Mechanism of Action:**
• Vonoprazan is a potassium-competitive acid blocker (P-CAB) that inhibits gastric acid secretion by targeting the potassium-binding site of the proton pump.
• It provides more rapid, potent, and sustained acid suppression compared to PPIs.
• **Advantages Over PPIs:**
• Faster onset of action.
• Stronger and more consistent acid suppression, including during the nighttime, when acid breakthrough is common with PPIs.
• Potential to improve symptoms in patients with refractory GERD and associated chronic cough.

#### 3. **Case Series Evidence:**

• In a small case series, vonoprazan was tested in three patients with refractory GERC who had failed to respond to 8 weeks of PPI therapy.
• **Outcomes:**
• All three patients experienced complete resolution of their chronic cough after switching to vonoprazan.
• This suggests that vonoprazan may be an effective alternative for patients with refractory GERC.

#### 4. **Clinical Implications:**

• Vonoprazan offers a promising therapeutic option for patients with GERD-induced chronic cough who do not respond to standard PPI therapy.
• It may be especially beneficial in cases where stronger and more consistent acid suppression is required.
• Given the limited data, larger studies and clinical trials are needed to confirm vonoprazan’s efficacy and safety in this patient population.

#### 5. **Considerations for Practice:**

• **Diagnosis:** Accurate diagnosis of GERD-induced chronic cough is essential to ensure appropriate treatment. This may involve pH monitoring, impedance testing, or response to therapeutic trials.
• **Treatment Algorithm:**
• For patients with refractory symptoms, switching from PPIs to vonoprazan may be a reasonable strategy.
• Lifestyle modifications (e.g., weight management, dietary changes, head-of-bed elevation) should also be emphasized.
• **Monitoring:** Patients should be monitored for symptom resolution and potential side effects of vonoprazan.

### Conclusion:

Vonoprazan represents a promising alternative for managing refractory GERD-induced chronic cough, particularly in cases where PPIs fail to provide adequate symptom control. While the initial evidence is encouraging, further research is needed to establish its role in broader clinical practice.