What is the recommended treatment and dosage of Vonoprazan (potassium-competitive acid blocker) for an adult patient with gastroesophageal reflux disease (GERD) and potential peptic ulcer disease, considering impaired renal function and liver disease?

Vonoprazan Dosing in GERD and Peptic Ulcer Disease with Renal and Hepatic Impairment

For an adult patient with GERD and potential peptic ulcer disease who has impaired renal and liver function, vonoprazan should be dosed at 10 mg once daily for healing of erosive esophagitis, with dose adjustments based on the severity of organ dysfunction as specified by FDA labeling. 1

Dosing Algorithm for Renal Impairment

For healing of erosive esophagitis:

• eGFR ≥30 mL/min: 20 mg once daily for 8 weeks 1
• eGFR <30 mL/min: 10 mg once daily for 8 weeks 1

For maintenance of healed erosive esophagitis or non-erosive GERD:

• No dose adjustment needed regardless of renal function—use standard 10 mg once daily 1

For H. pylori eradication (if indicated):

• eGFR ≥30 mL/min: 20 mg twice daily for 14 days 1
• eGFR <30 mL/min: Use is not recommended 1

Dosing Algorithm for Hepatic Impairment

For healing of erosive esophagitis:

• Child-Pugh Class A: 20 mg once daily for 8 weeks 1
• Child-Pugh Class B: 10 mg once daily for 8 weeks 1
• Child-Pugh Class C: 10 mg once daily for 8 weeks 1

For maintenance of healed erosive esophagitis or non-erosive GERD:

• No dose adjustment needed regardless of hepatic function—use standard 10 mg once daily 1

For H. pylori eradication (if indicated):

• Child-Pugh Class A: 20 mg twice daily for 14 days 1
• Child-Pugh Class B: Use is not recommended 1
• Child-Pugh Class C: Use is not recommended 1

Clinical Positioning: When to Use Vonoprazan

Vonoprazan should generally NOT be used as first-line therapy for GERD or peptic ulcer disease. 2, 3 The American Gastroenterological Association recommends the following treatment algorithm:

For GERD Management:

1. Start with standard once-daily PPI therapy for 4-8 weeks 3
2. Escalate to twice-daily PPI if inadequate response 3
3. Consider vonoprazan 20 mg daily only after documented failure of twice-daily PPI therapy in patients with confirmed acid-related reflux 3

Exception: Vonoprazan may be considered earlier in patients with severe erosive esophagitis (LA grade C/D) who have failed standard PPI therapy 3

For Peptic Ulcer Disease:

1. Begin with standard PPI therapy as first-line treatment 2, 3
2. Reserve vonoprazan 20 mg daily for PPI treatment failures 2, 3
3. Ensure ulcers are not secondary to non-acid processes (cancer, opportunistic infections, vasculitis, ischemia) before using vonoprazan 2

Efficacy Data Supporting Use

For peptic ulcer disease, vonoprazan demonstrates comparable healing rates to PPIs:

• Gastric ulcers: 94% healing at 8 weeks (vs. 94% with lansoprazole) 3
• Duodenal ulcers: 96% healing at 6 weeks (vs. 98% with lansoprazole) 3

For erosive esophagitis, vonoprazan shows superior efficacy in severe disease:

• LA grade A/B: Similar healing rates to PPIs (94% vs. 91%) 3
• LA grade C/D: Superior maintenance of healing (75-77% vs. 62% with lansoprazole) 3

Vonoprazan is particularly effective for H. pylori-associated ulcers compared to idiopathic or NSAID-related ulcers 3

Administration Instructions

• Take with or without food—no meal timing requirement 1
• Swallow tablets whole—do not chew or crush 1
• Missed dose for GERD: Take within 12 hours; if >12 hours passed, skip and resume normal schedule 1
• Missed dose for H. pylori: Take within 4 hours; if >4 hours passed, skip and resume normal schedule 1

Critical Cost Considerations

The primary limitation of vonoprazan is its markedly higher cost compared to both standard-dose and double-dose PPIs. 2, 3 This cost differential is the main reason for reserving vonoprazan as second-line therapy, particularly when clinical superiority over double-dose PPIs has not been clearly demonstrated 2

Safety Profile and Monitoring

Short-term safety appears comparable to PPIs, but long-term safety data are more limited. 3 Common adverse events include:

• Abdominal pain, constipation, diarrhea, nausea, dyspepsia 4

Important warnings:

• Acute tubulointerstitial nephritis has been reported—discontinue if suspected 1
• Clostridioides difficile-associated diarrhea risk may be increased—use shortest duration appropriate 1
• Serum gastrin levels may be elevated higher than with PPIs 5
• Gastric malignancy must be excluded in patients with suboptimal response 1

Pharmacologic Advantages Over PPIs

Vonoprazan offers several theoretical advantages that may be clinically relevant in select patients:

• Rapid onset: Achieves intragastric pH >4.0 within 4 hours of first dose 5
• Not affected by CYP2C19 polymorphisms: More consistent acid suppression across populations 3, 5
• Longer duration of action: Maintains acid suppression >24 hours 5
• No prodrug activation required: Direct mechanism of action 5

In PPI-refractory GERD patients, vonoprazan provides 88% improvement rate and 42% resolution rate. 6

Common Pitfalls to Avoid

• Do not prescribe vonoprazan as first-line therapy for mild GERD or PUD when PPIs would be more cost-effective 3
• Do not fail to document PPI failure before switching to vonoprazan 3
• Do not use in severe hepatic impairment (Child-Pugh B/C) for H. pylori eradication 1
• Do not use in severe renal impairment (eGFR <30) for H. pylori eradication 1
• Do not co-administer with rilpivirine-containing products—this is contraindicated 1