esomeprazole
Brand: Nexium
Prototype: omeprazole
Drug Class: proton pump inhibitor
Drug Family: GI agent
Subclass: S-isomer of omeprazole
Organ Systems: gastrointestinal
Mechanism of Action
S-enantiomer of omeprazole; slower CYP2C19 metabolism providing higher plasma levels; similar mechanism.
H+/K+-ATPase
Indications
- GERD
- erosive esophagitis
- H. pylori
- PUD
- Zollinger-Ellison
Contraindications
- rilpivirine
- atazanavir
Adverse Effects
Common
- headache
- diarrhea
- nausea
Serious
- hypomagnesemia
- C. diff
- fracture risk
Pharmacokinetics (ADME)
| Absorption | 89% bioavailability (less first-pass than omeprazole) |
| Distribution | moderate |
| Metabolism | CYP2C19 and CYP3A4 (less CYP2C19-dependent than omeprazole) |
| Excretion | renal |
| Half-life | 1-1.5 hours |
| Onset | 1-3 hours |
| Peak | 1-2 hours |
| Duration | 24+ hours |
| Protein Binding | 97% |
| Vd | 0.22 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| clopidogrel | less CYP2C19 inhibition than omeprazole but still present | moderate |
| atazanavir/rilpivirine | reduces absorption | major |
Nursing Considerations
- Same efficacy as omeprazole; less CYP2C19-dependent metabolism
- Slightly higher bioavailability due to less first-pass metabolism
- Take 30-60 min before meals
Clinical Pearls
- S-enantiomer: slower first-pass CYP2C19 metabolism — modestly higher systemic exposure than omeprazole
- Clinically equivalent to omeprazole despite pharmacokinetic differences
Safety Profile
Pregnancy safe
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.