Parbezol

What it is

Parbezol contains rabeprazole sodium, available as enteric coated tablets in strengths of 10 mg (equivalent to 9.42 mg rabeprazole) and 20 mg (equivalent to 18.85 mg rabeprazole). Rabeprazole sodium is a substituted benzimidazole belonging to the class of proton pump inhibitors that suppresses gastric acid secretion by specific inhibition of the H+/K+-ATPase enzyme at the secretory surface of the gastric parietal cell.

Approved indications

— Treatment and prevention of relapse of gastro-oesophageal reflux disease. — Symptomatic treatment of gastro-oesophageal reflux disease. — Treatment of duodenal ulcers. — Treatment of gastric ulcers. — Eradication of Helicobacter pylori in patients with peptic ulcer disease or chronic gastritis, in combination with clarithromycin and amoxicillin. — Healing of peptic ulcers in patients with Helicobacter pylori associated ulcers, in combination with clarithromycin and amoxicillin.

Dosing overview

No dosage adjustment is necessary in elderly patients. No dosage adjustment is necessary for patients with renal impairment. Parbezol should not be chewed or crushed, but should be swallowed whole and should be taken at the same time each day.

Key safety warnings

Symptomatic response to therapy with Parbezol does not preclude the presence of gastric malignancy; therefore the possibility of malignancy should be excluded prior to commencing treatment. Acute tubulointerstitial nephritis has been observed in patients taking proton-pump inhibitors including rabeprazole sodium, may occur at any point during therapy and is generally attributed to an idiopathic hypersensitivity reaction, and can progress to renal failure. Daily treatment with Parbezol over a long period of time (e.g. longer than three years) may lead to malabsorption of cyanocobalamin (vitamin B-12) caused by hypo- or achlorhydria. Hypomagnesaemia, symptomatic and asymptomatic, has been reported rarely in patients treated with proton pump inhibitors, with serious adverse events including tetany, arrhythmias and seizures; in most patients, treatment required magnesium replacement and discontinuation of the proton pump inhibitor. Observational studies suggest that proton pump inhibitor therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist or spine, particularly in patients who received high-dose and long-term therapy. Treatment with proton pump inhibitors may possibly increase the risk of gastrointestinal infections such as Clostridium difficile. Subacute cutaneous lupus erythematosus has been reported with the use of proton pump inhibitors; if lesions occur, especially in sun-exposed areas of the skin and if accompanied by arthralgia, the patient should seek medical help promptly and consider stopping Parbezol. Long-term use of Parbezol is associated with an increased risk of fundic gland polyps, and patients with large or ulcerated polyps may be at risk of gastrointestinal bleeding or small intestinal blockage; use the lowest dose and shortest duration appropriate to the condition being treated.

Contraindications

Parbezol is contraindicated in patients with known hypersensitivity to rabeprazole sodium, proton pump inhibitors or any ingredient of the product.

Regulatory history

Parbezol rabeprazole sodium 10 mg and 20 mg enteric coated tablet blister packs were first listed on the Australian Register of Therapeutic Goods on 9 July 2012.