vonoprazan
Brand: Voquezna
Prototype Drug
Drug Class: potassium-competitive acid blocker (P-CAB)
Drug Family: GI agent
Subclass: potassium-competitive acid blocker
Organ Systems: gastrointestinal
Mechanism of Action
Competitively and reversibly inhibits gastric H+/K+-ATPase by competing with potassium ions at the enzyme's potassium-binding site, achieving rapid, potent, and sustained acid suppression without requiring an acidic environment for activation.
H+/K+-ATPase (proton pump)
Indications
- erosive esophagitis
- H. pylori eradication (combination therapy)
- GERD
Contraindications
- hypersensitivity to vonoprazan
- concurrent rilpivirine use
- concurrent atazanavir use
Adverse Effects
Common
- diarrhea
- nausea
- abdominal pain
- upper respiratory tract infection
Serious
- Clostridium difficile infection
- hypomagnesemia
- acute interstitial nephritis
Pharmacokinetics (ADME)
| Absorption | oral bioavailability ~83%; not significantly affected by food |
| Distribution | 80% protein bound |
| Metabolism | hepatic via CYP3A4 (major) and CYP2B6/2C19 (minor) |
| Excretion | renal and fecal |
| Half-life | 9 hours |
| Onset | 0.5–1 hour |
| Peak | 1.5–2 hours |
| Duration | 24+ hours |
| Protein Binding | 80% |
| Vd | moderate |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| atazanavir | markedly reduced atazanavir absorption due to elevated gastric pH | major |
| rilpivirine | reduced rilpivirine absorption; contraindicated combination | major |
| strong CYP3A4 inhibitors | increased vonoprazan exposure | moderate |
Nursing Considerations
- Vonoprazan achieves more rapid and consistent acid suppression than PPIs; educate patients it works differently from traditional PPIs.
- Does not require activation by acid, so timing relative to meals is less critical than for PPIs.
- Monitor for C. difficile infection, particularly in hospitalized patients or those on antibiotics.
- Assess for concurrent use of HIV medications (rilpivirine, atazanavir) as these are absolute contraindications.
Clinical Pearls
- Unlike PPIs, vonoprazan acts via reversible potassium-competitive inhibition and does not require acid activation, resulting in a faster onset and more complete acid suppression.
- FDA-approved in combination with amoxicillin (dual therapy) or amoxicillin plus clarithromycin (triple therapy) for H. pylori eradication.
Safety Profile
Pregnancy avoid
Lactation avoid
Renal Adjustment Required
Hepatic Adjustment Required
TDM Not required
Guideline Update pending
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.