DrugindexOnline^{2nd edition}

Pronouncation: (ra-BE-pray-zole SO-dee-uhm)
Class: Proton pump inhibitor

Trade Names:
Aciphex
- Tablets, delayed-release 20 mg

Pariet (Canada)

Mechanism of Action

Pharmacology

Suppresses gastric acid secretion by blocking acid (proton) pump within gastric parietal cells.

Pharmacokinetics

Absorption

T _max is 2 to 5 hr. Oral bioavailability is about 52%.

Distribution

Protein binding is 96.3%.

Metabolism

Extensively metabolized in liver by CYP3A to sulfone metabolite and CYP2C19 to desmethyl rabeprazole. Thioether metabolite is formed by reduction of rabeprazole. These metabolites do not have significant antisecretory activity. Poor metabolizers of rabeprazole, CYP2C19 exhibits genetic polymorphism caused by deficiency (white patients 3% to 5%; Asian patients 17% to 20%).

Elimination

Plasma t _½ is 1 to 2 hr. Eliminated in urine (90% as thioether carboxylic acid, glucuronide and mercapturic acid); remainder recovered in feces. No unchanged drug recovered.

Special Populations

Hepatic Function Impairment

For chronic mild to moderate, AUC approximately doubled, elimination t _½ was 2 to 3 fold higher, total Cl decreased to less than half. For mild to moderate, C _max increased about 20% (not significant).

Elderly

AUC values doubled, C _max increased 60%.

Indications and Usage

Short-term treatment in healing and symptomatic relief of duodenal ulcers and erosive or ulcerative gastroesophageal reflux disease (GERD); maintaining healing and reducing relapse rates of heartburn symptoms in patients with GERD; treatment of daytime and nighttime heartburn and other symptoms associated with GERD; long-term treatment of pathological hypersecretory conditions, including Zollinger-Ellison syndrome and in combination with amoxicillin and clarithromycin to eradicate Helicobacter pylori .

Contraindications

Known hypersensitivity to substituted benzimidazoles.

Dosage and Administration

Healing of Duodenal Ulcers
Adults

PO 20 mg/day after the morning meal for 4 wk, additional therapy may be required for some patients.

Treatment of Erosive or Ulcerative GERD
Adults

PO 20 mg/day for 4 to 8 wk, an additional 8 wk may be considered for patients who do not heal.

Maintenance of Erosive or Ulcerative GERD
Adults

PO 20 mg/day.

Treatment of Symptomatic GERD
Adults

PO 20 mg once daily for 4 wk. An additional course of treatment may be considered if symptoms do not resolve after 4 wk.

Treatment of Pathological Hypersecretory Conditions
Adults

PO 60 mg/day. Doses up to 100 mg daily or 60 mg bid have been administered.

H. Pylori Eradication to Reduce Risk of Duodenal Ulcer Recurrence
Adults

PO 20 mg rabeprazole plus amoxicillin 1,000 mg plus clarithromycin 500 mg bid for 7 days with morning and evening meals.

Storage/Stability

Store tablets at controlled room temperature (59° to 86°F). Protect from moisture.

Drug Interactions

Drugs dependent on gastric pH for absorption (eg, digoxin, ketoconazole)

Plasma levels of digoxin may be increased, while ketoconazole concentrations may be decreased.

Warfarin

Increased INR and PT have been reported with concurrent rabeprazole.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Hypertension; MI; ECG abnormalities; migraine; syncope; angina pectoris; bundle branch block; palpitation; sinus bradycardia; tachycardia.

CNS

Headache (2%); insomnia; anxiety; dizziness; depression; nervousness; somnolence; hypertonia; neuralgia; vertigo; convulsion; abnormal dream, libido decreased, neuropathology, paresthesia, tremor, delirium, disorientation (postmarketing).

Dermatologic

Rash; pruritus; sweating; urticaria; alopecia; bullous eruptions, severe dermatologic reactions (including toxic epidermal necrolysis, Stevens-Johnson syndrome, erythema multiforme) (postmarketing).

EENT

Cataract; amblyopia; glaucoma; dry eyes; abnormal vision; tinnitus; otitis media.

GI

Diarrhea; nausea; abdominal pain; vomiting; dyspepsia; flatulence; constipation; dry mouth; eructation; gastroenteritis; rectal hemorrhage; melena; anorexia; mouth ulceration; stomatitis; dysphagia; gingivitis; increased appetite; abnormal stools; proctitis; colitis; esophagitis; glossitis; pancreatitis; cholelithiasis; cholecystitis.

Genitourinary

Cystitis; urinary frequency; dysmenorrhea; dysuria; kidney calculus; metrorrhagia; polyuria; interstitial nephritis (postmarketing).

Hematologic

Anemia; ecchymosis; lymphadenopathy; hypochromic anemia; agranulocytosis, hemolytic anemia, leukopenia, pancytopenia, thrombocytopenia (postmarketing).

Hepatic

Jaundice (postmarketing).

Metabolic

Hyperthyroidism; hypothyroidism; peripheral edema; edema; weight gain/loss; gout; dehydration; TSH elevations (postmarketing).

Respiratory

Dyspnea; asthma; epistaxis; laryngitis; hiccough; hyperventilation; interstitial pneumonia (postmarketing).

Miscellaneous

Asthenia; fever; allergic reaction; chills; malaise; substernal chest pain; neck rigidity; photosensitivity reaction; myalgia; arthritis; leg cramps; bone pain; arthrosis; bursitis; anaphylaxis, angioedema, coma, hyperammonemia, rhabdomyolysis, sudden death (postmarketing).

Precautions

Pregnancy

Category B .

Lactation

Undetermined.

Children

Safety and efficacy not established.

Gastric malignancy

Symptomatic response to rabeprazole does not preclude gastric malignancy.

Patient Information

• Explain name, dose, dosing frequency, action, and potential side effects of drug.
• Instruct patient to take each dose without regard to meals but to take with food if stomach upset occurs.
• Instruct patient to swallow tablets whole and not to split, crush, or chew the tablets.
• Remind patient that rabeprazole is to be taken every day and not as needed or only when symptoms are present.
• Remind patient that antacids may be taken concurrently with rabeprazole.
• Advise women to notify health care provider if pregnant, planning to become pregnant, or breastfeeding.
• Instruct patient to report any of the following to health care provider: bloody or coffee ground vomit; black tarry stools; recurrent heartburn; recurrent indigestion or abdominal pain; increasing need for antacid use; or bothersome side effects (eg, headache, constipation, gas).
• Instruct patient not to take any prescription or OTC medications, herbal preparations, or dietary supplements unless advised by health care provider.
• Advise patient that follow-up visits may be required to monitor therapy and to keep appointments.