Vonoprazan suppresses basal and stimulated gastric acid secretion at the secretory surface of the gastric parietal cell through inhibition of the H+, K+-ATPase enzyme system in a potassium competitive manner. Because this enzyme is regarded as the acid (proton) pump within the parietal cell, vonoprazan has been characterized as a type of gastric proton-pump inhibitor, in that it blocks the final step of acid production. Vonoprazan does not require activation by acid. Vonoprazan may selectively concentrate in the parietal cells in both the resting and stimulated states. Vonoprazan binds to the active proton pumps in a noncovalent and reversible manner. Amoxicillin is an antibacterial drug. Clarithromycin is a macrolide antimicrobial drug [see Microbiology (12.4)]. Acid suppression enhances the replication of H. pylori bacteria and the stability and effectiveness of antimicrobials in the treatment of H. pylori infection.

VOQUEZNA is a potassium-competitive acid blocker indicated:

• for healing of all grades of erosive esophagitis and relief of heartburn associated with erosive esophagitis in adults. 
•  to maintain healing of all grades of erosive esophagitis and relief of heartburn associated with erosive esophagitis in adults. 
• for the relief of heartburn associated with non-erosive gastroesophageal reflux disease in adults.
• in combination with amoxicillin and clarithromycin for the treatment of Helicobacter pylori (H. pylori) infection in adults.
• in combination with amoxicillin for the treatment of H. pylori infection in adults. 

Recommended Dosage:

• Healing of Erosive Esophagitis: 20 mg once daily for 8 weeks.
• Maintenance of Healed Erosive Esophagitis: 10 mg once daily for up to 6 months.
• Relief of Heartburn Associated with Non-Erosive Gastroesophageal Reflux Disease: 10 mg once daily for 4 weeks.
• Treatment of H. pylori Infection: see full prescribing information.
• See also full prescribing information for the recommended dosage by indication for patients with renal or hepatic impairment. 

Most common adverse reactions in VOQUEZNA-treated patients are:

• Healing of Erosive Esophagitis (≥2%): gastritis, diarrhea, abdominal distension, abdominal pain, and nausea. (6.1)
• Maintenance of Healed Erosive Esophagitis (≥3%): gastritis, abdominal pain, dyspepsia, hypertension, and urinary tract infection. (6.1)
• Relief of Heartburn Associated with Non-Erosive Gastroesophageal Reflux Disease (≥2%): abdominal pain, constipation, diarrhea, nausea, and urinary tract infection. (6.1)
• Treatment of H. pylori Infection (≥2%): diarrhea, dysgeusia, vulvovaginal candidiasis, abdominal pain, headache, hypertension, and nasopharyngitis. (6.1)

• Known hypersensitivity to vonoprazan or any component of VOQUEZNA.
• Rilpivirine-containing products. 

• Gastric Malignancy: Symptomatic response to treatment does not preclude the presence of gastric malignancy; consider additional follow-up and diagnostic testing. (5.1)
• Acute Tubulointerstitial Nephritis: Discontinue treatment and evaluate patients. (5.2)
• Clostridioides difficile-Associated Diarrhea (CDAD): May be associated with an increased risk; use the shortest duration of treatment appropriate to the condition. (5.3)
• Bone Fracture, including Osteoporosis-related Fracture: Use the shortest duration of treatment appropriate to the condition. (5.4)
• Severe Cutaneous Adverse Reactions: Discontinue at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation. (5.5)
• Vitamin B12 (Cobalamin) Deficiency: Long-term use may lead to malabsorption or deficiency; consider further workup if clinical symptoms are present. (5.6)
• Hypomagnesemia and Mineral Metabolism: Hypomagnesemia may lead to hypocalcemia and/or hypokalemia. Consider monitoring magnesium and calcium levels in at-risk patients, or if there is concomitant use of digoxin or other drugs that cause hypomagnesemia. (5.7)
• Interactions with Investigations for Neuroendocrine Tumors: Increased chromogranin A (CgA) levels may interfere with diagnostic investigations; temporarily stop
• VOQUEZNA at least 4 weeks before assessing CgA levels. (5.8, 7)
• Fundic Gland Polyps: Risk increases with long-term use; use the shortest duration of treatment appropriate to the condition. (5.9)