Rabeprazole belongs to a 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 a 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 a half-life of 78 seconds. It inhibits acid transport in porcine gastric vesicles with a half-life of 90 seconds.

ACIPHEX is a proton-pump inhibitor (PPI) indicated in adults for: • Healing of Erosive or Ulcerative Gastroesophageal Reflux Disease (GERD. • Maintenance of Healing of Erosive or Ulcerative GERD. • Treatment of Symptomatic GERD. • Healing of Duodenal Ulcers. • Helicobacter pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence • Treatment of Pathological Hypersecretory Conditions, Including Zollinger-Ellison Syndrome. In adolescent patients 12 years of age and older for: • Short-term treatment of Symptomatic GERD. In pediatric patients 1 to 11 years of age for: • Treatment of GERD.

ACIPHEX Delayed-Release Tablets should be swallowed whole. The tablets should not be chewed, crushed, or split. ACIPHEX Sprinkle Delayed-Release Capsules should be opened and the granule contents sprinkled on a spoonful of soft food or liquid (e.g., applesauce). Whole dose should be taken within 15 minutes of being sprinkled. The granules should not be chewed or crushed. Dose should be taken 30 minutes before a meal. See package insert for complete information.

• In the adult studies (4 to 8 weeks), adverse reactions that occurred at a rate greater than 2% and greater than placebo included pain, pharyngitis, flatulence, infection, and constipation. • In studies of pediatric and adolescent patients (ages 1 to 16 years, and up to 36 weeks exposure) adverse reactions that occurred at a rate of ≥5% of patients included abdominal pain, diarrhea, and headache.

• History of hypersensitivity to rabeprazole.

• Symptomatic response to therapy with rabeprazole does not preclude the presence of gastric malignancy. • Use with warfarin: Monitor for increases in INR and prothombin time. • Acute interstitial nephritis has been observed in patients taking PPIs. • Cyanocobalamin (vitamin B-12) Deficiency: Daily long-term use (e.g., longer than 3 years) may lead to malabsorption or a deficiency of cyanocobalamin • PPI therapy may be associated with increased risk of Clostridium difficile associated diarrhea. • Bone fracture: Long-term and multiple daily dose PPI therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine • Hypomagnesemia has been reported rarely with prolonged treatment with PPIs.