Esomeprazole

The S-isomer proton pump inhibitor with improved acid suppression.

What is Esomeprazole?

Esomeprazole is the S-enantiomer of omeprazole and belongs to the proton pump inhibitor (PPI) class of medicines.

It provides more consistent and prolonged acid suppression.

History & Background

Esomeprazole was developed to improve the pharmacokinetics of omeprazole, offering better bioavailability and sustained acid control.

Chemical Structure & Properties

• IUPAC name: (S)-5-methoxy-2-[(4-methoxy-3,5-dimethylpyridin-2-yl)methylsulfinyl]-1H-benzimidazole
• Molecular formula: C₁₇H₁₉N₃O₃S
• Molar mass: 345.42 g/mol
• Functional groups: Benzimidazole, sulfoxide

Mechanism of Action

Esomeprazole irreversibly inhibits the H⁺/K⁺-ATPase proton pump in gastric parietal cells, resulting in:

• Strong suppression of gastric acid secretion
• Healing of acid-related mucosal injury

Pharmacokinetics

• Absorption: Good oral absorption (enteric-coated)
• Peak plasma time: 1–2 hours
• Metabolism: Liver (CYP2C19, CYP3A4)
• Half-life: ~1.3 hours
• Duration of action: Up to 24 hours

Medical Uses

• Gastroesophageal reflux disease (GERD)
• Erosive esophagitis
• Peptic ulcer disease
• H. pylori eradication (combination therapy)

Dosage Guidelines

Adults: 20–40 mg once daily (before meals)

Severe GERD: 40 mg once daily

⚠️ Swallow whole. Do not crush or chew.

Side Effects

• Headache
• Abdominal pain
• Diarrhea
• Nausea

Warnings & Precautions

• Risk of vitamin B12 deficiency with long-term use
• Possible hypomagnesemia
• Use lowest effective dose

Drug Interactions

• Clopidogrel (reduced activation)
• Warfarin
• Diazepam

Frequently Asked Questions

Is esomeprazole stronger than omeprazole? – More consistent.

Does it work instantly? – Full effect in 2–3 days.

Best time to take? – Morning before food.

Safe long-term? – Yes, if monitored.

⚠️ Educational content only. Not a substitute for professional medical advice.