Potassium Competitive Acid Blocker


Potassium Competitive Acid Blocker, PCAB, Vonoprazin, Voquezna

  • Indications
  1. Erosive Esophagitis
  • Mechanism
  1. Potassium Competitive Acid Blocker (PCAB)
  2. Similar mechanism as Proton Pump Inhibitors (PPIs)
  3. In addition to blocking active proton pumps (as with PPIs), PCABs also block resting proton pumps
    1. Allows for PCAB onset of activity within hours (as compared with days for PPIs)
    2. PCABs may be taken with or without food (contrast with PPIs taken 60 minutes before eating)
  • Dosing
  1. Healing of Erosive Esophagitis and GERD Relief
    1. Vonoprazin 20 mg orally daily for 8 weeks
    2. Decrease dose to 10 mg orally daily if GFR <30 ml/min
  2. Maintenance of Healed Erosive Esophagitis and GERD Relief
    1. Vonoprazin 10 mg orally daily for up to 6 months
  3. Helicobacter Pylori
    1. Packaged with antibiotics (Amoxicillin and Clarithromycin)
    2. However, no evidence for greater efficacy for PCABs than the much lower cost Proton Pump Inhibitors
  • Efficacy
  1. Vonoprazin 20 mg is similar to Lansoprazole (Prevacid) 30 mg for erosive Esophagitis healing at 4 weeks
  2. Vonoprazin is $650/month at the time of release in 2024
  • Adverse Effects
  1. Diarrhea
  2. Nausea
  3. Longterm adverse effects are similar to Proton Pump Inhibitors
    1. Increased Fracture risk
    2. Clostridioides difficile
  • Safety
  1. Unknown safety in pregnancy
  2. Unknown safety in Lactation
  • Drug Interactions
  1. CYP3A4 Inducers
    1. Decrease Vonoprazin efficacy
  • References
  1. (2024) Presc Lett 31(1): 5