Vonoprazan + Amoxicillin

• Helicobacter pylori Infection Eradication:
  Used as part of triple or dual therapy regimens (typically combined with clarithromycin or other antibiotics) to eradicate H. pylori infection associated with:
• Peptic ulcer disease (gastric and duodenal ulcers)
• Chronic gastritis related to H. pylori
• Prevention of recurrence of H. pylori-associated ulcers
• Gastric mucosa-associated lymphoid tissue (MALT) lymphoma linked to H. pylori
• Adjunct Treatment in Acid-Related Disorders:
  Vonoprazan’s potent acid suppression enhances antibiotic efficacy and mucosal healing in acid-related diseases.

• Adults:
• Vonoprazan: 20 mg orally twice daily (before breakfast and dinner)
• Amoxicillin: 750 mg orally twice daily or 500 mg three times daily
• Duration: Usually 7 days, adjusted per local guidelines and clinical judgment
• Elderly:
• Same dosing as adults; careful monitoring for renal function and adverse effects recommended.
• Pediatrics:
• Safety and efficacy have not been established; use not routinely recommended.
• Renal Impairment:
• Amoxicillin dose adjustments may be required in severe renal dysfunction.
• Vonoprazan generally requires no dose adjustment.
• Hepatic Impairment:
• Use caution; no specific dose adjustment established.
• Administration Route:
  Oral administration with water; ideally taken before meals to optimize acid suppression and antibiotic effectiveness.

• Vonoprazan is a potassium-competitive acid blocker (P-CAB) that reversibly inhibits the gastric H+,K+-ATPase enzyme (proton pump) in gastric parietal cells by competitively blocking potassium binding. This leads to rapid, potent, and sustained suppression of gastric acid secretion, increasing gastric pH and creating an environment unfavorable for H. pylori survival.
• Amoxicillin is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins, resulting in bacterial cell lysis and death. Its bactericidal activity targets actively dividing H. pylori organisms.
• The elevated gastric pH caused by vonoprazan enhances the stability and antibacterial efficacy of amoxicillin, improving eradication rates.

• Vonoprazan:
• Rapid oral absorption, peak plasma concentration in 1–2 hours
• High bioavailability, unaffected by food intake
• Metabolized primarily by CYP3A4, with minor involvement of CYP2B6, CYP2C19, and CYP2D6
• Elimination via urine (~65%) and feces (~30%) as metabolites
• Plasma half-life approximately 7 hours
• Amoxicillin:
• Well absorbed orally; peak plasma levels within 1–2 hours
• Widely distributed in body fluids and tissues
• Minimal metabolism
• Eliminated primarily unchanged via renal excretion
• Half-life about 1 hour; prolonged in renal impairment

• Pregnancy:
• Vonoprazan: Limited human data; animal studies do not show teratogenicity. Use only if clearly needed.
• Amoxicillin: FDA Category B; generally considered safe during pregnancy.
• Lactation:
• Vonoprazan: Unknown if excreted in breast milk; caution advised.
• Amoxicillin: Excreted in breast milk in low concentrations; generally compatible with breastfeeding.

• Vonoprazan: Acid suppressant – Potassium-competitive acid blocker (P-CAB)
• Amoxicillin: Antibiotic – Beta-lactam (penicillin class)

• Known hypersensitivity to vonoprazan, amoxicillin, penicillin antibiotics, or any excipients.
• History of severe allergic reaction (anaphylaxis) to beta-lactam antibiotics.
• Concurrent use with rilpivirine-containing medications (due to drug interaction with vonoprazan).
• Severe renal impairment without appropriate dose adjustment for amoxicillin.

• Monitor for hypersensitivity reactions including anaphylaxis with amoxicillin.
• Use caution in patients with gastrointestinal diseases such as inflammatory bowel disease or colitis.
• Monitor renal function, especially in elderly or renally impaired patients.
• Clostridium difficile-associated diarrhea may occur with amoxicillin use; promptly evaluate any persistent diarrhea.
• Vonoprazan-induced elevation of gastric pH may alter absorption of other drugs dependent on acidic environment.

Common:

• Gastrointestinal: Diarrhea, nausea, abdominal pain, dyspepsia, flatulence
• Headache
• Taste disturbance (amoxicillin)

Serious but Rare:

• Allergic reactions: rash, urticaria, Stevens-Johnson syndrome, anaphylaxis
• Elevated liver enzymes (vonoprazan)
• Clostridium difficile infection

• Vonoprazan inhibits CYP3A4; may increase plasma concentrations of CYP3A4 substrates.
• Vonoprazan decreases rilpivirine plasma levels; concomitant use contraindicated.
• Increased gastric pH may reduce absorption of drugs needing acidic environment (e.g., ketoconazole).
• Amoxicillin may reduce efficacy of oral contraceptives.
• No significant interaction with alcohol documented, but alcohol may exacerbate GI side effects.

• Vonoprazan-based triple therapy increasingly recommended as a first-line option for H. pylori eradication, showing higher eradication rates and faster acid suppression compared to PPI-based regimens.
• Treatment duration generally 7 days, with some guidelines extending to 14 days in resistant infections.
• No major new safety concerns have emerged; safety profile remains consistent.

• Store tablets at 20°C to 25°C (68°F to 77°F).
• Protect from moisture and light; keep in original tightly closed container.
• Do not freeze.
• Keep out of reach of children.