Rabeprazole is an antiulcer drug in the class of proton pump inhibitors. It was developed by Eisai Co. and is marketed by Janssen-Cilag as rabeprazole sodium under the brand names Aciphex and Pariet.

Pharmacology

Rabeprazole is a prodrug (metabolized by the cytochrome P450 (or CYP450)) - in the acid environment of the parietal cells it turns into active sulphenamide form associated with cysteine of H+, K+ATPase (proton pump). Rabeprazole inhibits (partly reversibly) H+, K+ATPase of the coating gastric cells and dose-dependent oppresses basal and stimulated gastric acid secretion. Rabeprazole has anti Helicobacter pylori activity (MIC 4-16 mg/ml) and shows synergistic activity with some antibiotics. Rabeprazole has been demonstrated to be effective in patients with pathological hypersecretory activity (incl. Zollinger-Ellison Syndrome).

Indications and usage

• gastric ulcer
• peptic ulcer (PUD)
• Maintenance of Healing of Erosive or Ulcerative GERD
• Healing of Erosive and Ulcerative GERD
• Healing of Duodenal Ulcers.
• Treatment of Symptomatic GERD
• Treatment of Pathological Hypersecretory conditions (Zollinger-Ellison)
• Helicobactor Pylori Eradication to Reduce Risk of Duodenal Ulcer Recurrence

Contraindications

• hypersensitivity to Rabeprazole, substituted benzimidazoles or any of components of its pharmaceutical forms.
• pregnancy
• lactation

Restriction of usage

• acute hepatic failure
• pediatric use in patients under 18 years of age (there are insufficient data about safety and efficiency of Rabeprazole in this group of patients)

Side effects

Rabeprazole Adverse reactions/Side effects include:

• In clincal trials the most common side effect assessed as possibly or probably related to ACIPHEX was Headache in 2.4% of patients vs 1.6% taking placebo.
• diarrhea
• vomiting
• nausea
• abdominal pains
• constipation
• meteorism
• dry mouth
• increased or decreased appetite
• asthenia
• headache
• sleeplessness
• vertigo
• thrombocytopenia
• granulocytopenia
• leukocytopenia
• skin eruption
• erythema
• myalgia
• arthralgia
• muscle or bone pain

Drug interactions

Rabeprazole decreases the concentration of ketoconazole in the plasma (in 33%), increases the concentration of digoxin (in 22%), and does not interact with liquid antiacids. Rabeprazole is compatible with any medicine metabolized by the CYP450 (theophylline, warfarin, diazepam, phenytoin).

Overdosage

There is no available data on symptoms of rabeprazole overdose.

How supplied

Rabeprazole as Aciphex,Rabeloc, Pariet is supplied in:

• Tablet, Enteric-Coated; 10mg
• Tablet, Enteric-Coated; 20mg

References

• Morii M, Takata H, Fujisaki H, Takeguchi N., The potency of substituted benzimidazoles such as E3810, omeprazole, Ro 18-5364 to inhibit gastric H+, K(+)-ATPase is correlatedwith the rate of acid-activation of the inhibitor, Biochem. Pharmacol. 1990 Feb 15;39(4):661-7.
• Prakash A, Faulds D., Rabeprazole, Drugs. 1998 Feb;55(2):261-7; discussion 268.