Medical Editor: Jay Marks, M.D.

GENERIC NAME: rabeprazole

BRAND NAME: Aciphex

DRUG CLASS AND MECHANISM: Rabeprazole is an oral drug that is used for the treatment of conditions caused by acid. It is in a class of drugs called proton pump inhibitors or PPIs which block the production of acid by the stomach. Other drugs in the same class include lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonix), and esomeprazole (Nexium). PPIs are used for the treatment of acid-caused conditions such as stomach and duodenal ulcers, gastroesophageal reflux disease (GERD) and Zollinger-Ellison Syndrome. Rabeprazole, like other PPIs, blocks the enzyme in the wall of the stomach that makes and secretes acid into the stomach. By blocking the enzyme, the secretion of acid into the stomach is decreased, and this allows ulcers in the stomach and esophagus to heal.

GENERIC AVAILABLE: No.

PRESCRIPTION: Yes.

PREPARATIONS: Tablets: 20 mg

STORAGE: Store at room temperature, 15-30°C (59-86°F). Keep away from moisture.

PRESCRIBED FOR: Rabeprazole is used for treating ulcers of the stomach and duodenum, erosive or ulcerative gastroesophageal reflux disease (GERD) and Zollinger-Ellison Syndrome (in which there is overproduction of acid caused by tumors). It also is used with antibiotics for eradicating Helicobacter pylori infections of the stomach that, along with acid, are responsible for many ulcers.

DOSING: For healing ulcerative or erosive GERD, the recommended dose for adults is 20 mg daily for 4-8 weeks. If healing does not occur after 8 weeks, another 8 week course may be considered. The recommended maintenance dose is 20 mg daily. Heartburn due to GERD is treated with 20 mg daily for 4 weeks and an additional 4 weeks if symptoms do not resolve. Ulcers are treated with 20 mg daily for 4 weeks. For the management of Zollinger-Ellison Syndrome, the starting dose for adults is 60 mg daily, and the dose is adjusted based on improvement in symptoms, healing of ulcers, or the effectiveness of acid suppression. Doses of 100 mg per day and 60 mg twice daily have been used in some patients with Zollinger-Ellison Syndrome. The regimen for eradication of Helicobacter pylori is rabeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg all given twice daily (morning and evening) for 7 days.

Tablets should be swallowed whole and should not be crushed, split or chewed. Rabeprazole can be taken with or without meals since food has little effect on its absorption.

DRUG INTERACTIONS: There have been reports of an increase in the effect of the blood thinner, warfarin, by rabeprazole which theoretically could lead to increased bleeding. Patients taking warfarin should be monitored more frequently if the begin taking rabeprazole.

Rabeprazole may reduce the elimination of cyclosporin in the liver, thereby increasing cyclosporin levels in the blood and potentially lead to cyclosporin toxicity.

The absorption of certain drugs may be affected by changes in stomach acidity. Rabeprazole and other PPIs that reduce stomach acid reduce the absorption and concentration in blood of ketoconazole (Nizoral) and increase the absorption and concentration in blood of digoxin (Lanoxin). This may lead to reduced effectiveness of ketoconazole or increased digoxin toxicity, respectively.

PREGNANCY: Use in pregnant women has not been adequately evaluated.

NURSING MOTHERS: Rabeprazole has not been studied in nursing women.

SIDE EFFECTS: Rabeprazole like other PPIs has few side effects. The most common side effects are diarrhea, nausea, vomiting, constipation, rash and headaches. Dizziness, nervousness, abnormal heartbeat, muscle pain, weakness, leg cramps and water retention rarely occur.

References: Aciphex Full Prescribing Information, 2003. Manufactured and Marketed by Eisai Inc., Teaneck, NJ 07666

Reference: FDA Prescribing Information