Gastrointestinal/Proton pump inhibitor

Proton pump inhibitors

also: omeprazole · lansoprazole · pantoprazole · esomeprazole · PPI

Overview

The most effective acid suppressants — GORD, peptic ulcers, H. pylori eradication and ulcer prophylaxis. Long-term risks and the clopidogrel interaction are the exam points.

Mechanism

Irreversibly inhibit the H⁺/K⁺-ATPase ("proton pump") on the gastric parietal cell → profound, sustained suppression of acid secretion.

Indications

GORD / dyspepsia
Peptic ulcer disease + NSAID-ulcer prophylaxis
H. pylori eradication (with 2 antibiotics)
Upper GI bleeding (high-dose IV)

The agents

Omeprazole / esomeprazolePPI

Omeprazole/esomeprazole inhibit CYP2C19 → reduce clopidogrel activation (use lansoprazole/pantoprazole).

Lansoprazole / pantoprazolePPI

Preferred with clopidogrel.

Adverse effects

Hyponatraemia, hypomagnesaemiacommon

Check Mg on long-term use.

Increased C. difficile / enteric infection riskcommon

Osteoporosis/fractures, B12 deficiency (long-term)common

Masks gastric cancer (review alarm symptoms)serious

Don't treat undiagnosed dysphagia/weight loss/GI bleed without endoscopy.

Cautions & contraindications

Omeprazole/esomeprazole + clopidogrelall

↓clopidogrel efficacy — switch to lansoprazole/pantoprazole.

Stop 2 weeks before urea breath test / endoscopy for H. pyloriall

False negatives.

Interactions

CYP2C19 (clopidogrel); reduces absorption of pH-dependent drugs

Monitoring & kinetics

Mg/Na on long-term; review need + deprescribe; alarm symptoms

Oral OD (before food); IV high-dose for acute upper GI bleed.

Source: NICE CG184 — GORD / dyspepsia · BNF — PPIs