rabeprazole
Brand: Aciphex
Prototype: omeprazole
Drug Class: proton pump inhibitor
Drug Family: GI agent
Subclass: second-generation PPI
Organ Systems: gastrointestinal
Mechanism of Action
Irreversibly inhibits the gastric H+/K+-ATPase enzyme in parietal cells, blocking the final step of acid secretion regardless of stimulus.
H+/K+-ATPase (proton pump)
Indications
- GERD
- duodenal ulcer
- H. pylori eradication (combination therapy)
- hypersecretory conditions (Zollinger-Ellison syndrome)
Contraindications
- hypersensitivity to PPIs or benzimidazoles
Adverse Effects
Common
- headache
- diarrhea
- nausea
- abdominal pain
Serious
- Clostridium difficile infection
- hypomagnesemia (long-term use)
- bone fracture risk (long-term use)
- acute interstitial nephritis
Pharmacokinetics (ADME)
| Absorption | enteric-coated; absorbed in small intestine; bioavailability ~52% |
| Distribution | 96% protein bound |
| Metabolism | hepatic via CYP2C19 and CYP3A4; less CYP2C19-dependent than omeprazole |
| Excretion | renal (~90%) and fecal |
| Half-life | 1–2 hours |
| Onset | 1 hour |
| Peak | 2–5 hours |
| Duration | 24 hours |
| Protein Binding | 96% |
| Vd | 0.34 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| methotrexate | reduced renal excretion of methotrexate | major |
| clopidogrel | minimal CYP2C19 interaction compared to omeprazole | minor |
| atazanavir | reduced absorption of atazanavir due to increased gastric pH | major |
Nursing Considerations
- Administer 30 minutes before meals for optimal efficacy; swallow tablet whole without crushing.
- Monitor for signs of hypomagnesemia (muscle cramps, tremors, irregular heartbeat) in patients on long-term therapy.
- Assess for concurrent use of clopidogrel; rabeprazole has less CYP2C19 interaction than omeprazole.
- Educate patients that PPIs are for short-term use unless otherwise prescribed; review indication at each visit.
Clinical Pearls
- Among PPIs, rabeprazole has the least dependence on CYP2C19 genotype, making it more predictable in poor metabolizers.
- Avoid concomitant use with atazanavir or rilpivirine as increased gastric pH dramatically reduces their absorption.
Safety Profile
Pregnancy generally-safe
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
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