Last reviewed 2026-04-20 · How we verify

Aciphex (rabeprazole)

Aciphex works by irreversibly inhibiting the potassium-transporting ATPase enzyme in the stomach lining, reducing acid production.

Aciphex (rabeprazole) is a small molecule Proton Pump Inhibitor (PPI) developed by Eisai Inc. and currently owned by Waylis Therap. It targets the potassium-transporting ATPase enzyme to reduce stomach acid production. Aciphex is approved to treat various conditions, including gastroesophageal reflux disease, duodenal ulcers, and pathological gastric hypersecretory conditions. The drug is off-patent and has multiple generic manufacturers. Key safety considerations include its short half-life and moderate bioavailability.

At a glance

Mechanism of action

Rabeprazole belongs to class of antisecretory compounds (substituted benzimidazole proton-pump inhibitors) that do not exhibit anticholinergic or histamine H2-receptor antagonist properties, but suppress gastric acid secretion by inhibiting the gastric H+, K+ATPase at the secretory surface of the gastric parietal cell. Because this enzyme is regarded as the acid (proton) pump within the parietal cell, rabeprazole has been characterized as gastric proton-pump inhibitor. Rabeprazole blocks the final step of gastric acid secretion.In gastric parietal cells, rabeprazole is protonated, accumulates, and is transformed to an active sulfenamide. When studied in vitro, rabeprazole is chemically activated at pH 1.2 with half-life of 78 seconds. It inhibits acid transport in porcine gastric vesicles with half-life of 90 seconds.

Approved indications

• Duodenal Ulcer due to H. Pylori
• Duodenal ulcer disease
• Gastroesophageal reflux disease
• Maintenance of Healing Gastroesophageal Reflux
• Multiple endocrine adenomas
• Pathological Gastric Hypersecretory Condition
• Peptic ulcer
• Systemic mast cell disease
• Zollinger-Ellison syndrome

Common side effects

• pain
• pharyngitis
• flatulence
• infection
• constipation
• diarrhea
• taste perversion
• headache
• vomiting
• nausea
• dry mouth
• dizziness

Drug interactions

• clopidogrel
• dasatinib
• delavirdine
• erlotinib
• nelfinavir
• ponatinib
• rilpivirine
• risedronic acid
• zalcitabine

Key clinical trials

• Modular Clinical Pharmacology Study to Evaluate the Drug-drug Interaction Potential and Relative Bioavailability of Saruparib (PHASE1)
• Effect of ZaStaprazan on Platelet Reactivity of Clopidogrel After PercuTaneous CoronAry InteRvention (PHASE4)
• A Study to Evaluate the Effect of Food and Proton Pump Inhibitor on the Pharmacokinetics of ZN-A-1041 in Healthy Participants (PHASE1)
• The Impact of Helicobacter Pylori Eradication on the Vaginal Microecology Change
• Yiwei Jiaohuang Ointment for Gastrointestinal Bleeding Associated With Oral Antithrombotic Agents (EARLY_PHASE1)
• Efficacies of Bismuth-amoxicillin-vonoprazan Triple Therapy and Bismuth Quadruple Therapy (NA)
• Efficacies of Bismuth-amoxicillin-vonoprazan Triple Therapy, Vonoprazan-amoxicillin Dual Therapy and Proton Pump Inhibitor-based Standard Triple Therapy for Hp Eradication (NA)
• Potassium-Competitive Acid Blocker Versus pROton-Pump Inhibitor for GastroproTECTion Strategies In Patients at High Gastro-Intestinal Bleeding Risk Receiving Antithrombotic Therapy (PHASE4)

Primary sources

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