Proton pump inhibitors

PPIs are prodrugs. They collect in the acidic canaliculi of gastric parietal cells, where acid turns them into an active sulfenamide that binds the H+/K+ ATPase (the proton pump) through covalent disulfide bonds. This shuts off the last step of acid secretion, basal and stimulated alike, and because the bond is irreversible the effect outlasts the drug's short stay in the blood.

• OmeprazoleA proton pump inhibitor for reflux disease, peptic ulcers, H. pylori eradication with antibiotics and Zollinger-Ellison syndrome.
• EsomeprazoleAs one isomer of omeprazole, it shares omeprazole's side effects and its CYP2C19 interaction with clopidogrel.
• LansoprazoleA proton pump inhibitor for reflux disease, duodenal, gastric and NSAID-related ulcers, H. pylori eradication and Zollinger-Ellison syndrome.
• PantoprazoleIts label finds no clinically important effect on clopidogrel, whereas the omeprazole and esomeprazole labels advise avoiding that combination.

• Gastroesophageal reflux disease and erosive esophagitis
• Gastric and duodenal ulcers
• H. pylori eradication, with antibiotics
• Preventing ulcers in people taking NSAIDs
• Zollinger-Ellison syndrome

• C. difficile diarrheaKnown forSerious
• Hip, wrist and spine fractures with long-term useKnown forSerious
• Low magnesium (hypomagnesemia) with long-term useKnown forSerious
• Headache
• Diarrhea
• Abdominal pain
• Vitamin B12 deficiency after years of use
• Acute interstitial nephritisSerious
• Cutaneous or systemic lupus erythematosus
• Severe skin reactions (such as SJS/TEN)Serious

What the class has in common. Each drug's card has its own, and Known for marks what an exam expects you to know.

• Symptom relief does not rule out stomach cancer: investigate a poor response or an early relapse, especially in older adults.
• They lower absorption of drugs that need stomach acid; all PPIs are contraindicated with rilpivirine.
• Omeprazole and esomeprazole inhibit CYP2C19 and weaken clopidogrel; pantoprazole's label finds no important effect.
• Use the shortest course that works: fracture, low magnesium, B12 and fundic gland polyp risks grow with long use.

Written for biofideX in plain words, after checking these references:

• Proton Pump Inhibitor (NCI Thesaurus)
• Omeprazole delayed-release capsules: label (DailyMed)
• Esomeprazole magnesium delayed-release capsules: label (DailyMed)
• Pantoprazole sodium delayed-release tablets: label (DailyMed)
• Omeprazole (NHS)

For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.