FOSRENOL

What it is

FOSRENOL is lanthanum carbonate hydrate presented as chewable tablets. Each tablet contains lanthanum carbonate hydrate corresponding to 500 mg, 750 mg, or 1000 mg lanthanum.

Approved indications

— Treatment of hyperphosphataemia in adults with chronic renal failure on haemodialysis or continuous ambulatory peritoneal dialysis (CAPD).

Dosing overview

For patients taking FOSRENOL for the first time, the starting dose may be determined individually based on serum phosphate concentration: 750 mg daily for pre-treatment serum phosphate >1.8 and ≤2.4 mmol/L; 1500 mg daily for >2.4 and ≤2.9 mmol/L; and 2250 mg daily for >2.9 mmol/L. FOSRENOL should be taken with or immediately after food, with the daily dose divided between meals, three times daily. Serum phosphate levels should be monitored and the dose of FOSRENOL titrated every 2–3 weeks until an acceptable serum phosphate level is reached, with regular monitoring thereafter. Control of serum phosphate level has been demonstrated at doses from 750 mg with most patients achieving acceptable serum phosphate levels at 1500–3000 mg lanthanum per day. FOSRENOL tablets must be chewed completely before swallowing. The tablets may be crushed as an aid to chewing. Intact tablets must not be swallowed whole.

Key safety warnings

Tissue deposition of lanthanum, particularly in bone, liver, and the stomach wall, has been shown with FOSRENOL in animal studies. Deposition of lanthanum in bone has been studied in long-term studies demonstrating that bone lanthanum concentration had no apparent effect on bone health or treatment outcome for up to 4.5 years. There is no clinical data examining the potential deposition of lanthanum in other tissues. The long-term clinical effects of lanthanum deposition in tissues are not known. Cases of gastrointestinal obstruction, ileus, subileus, and gastrointestinal perforation have been reported in association with lanthanum, some requiring surgery or hospitalisation. Some cases are found to have lanthanum deposition or product residue in the gastrointestinal tract. Exercise caution in all patients predisposed to gastrointestinal obstruction, ileus, subileus and perforation; for example, those with altered gastrointestinal anatomy (such as diverticular disease, peritonitis, history of gastrointestinal surgery, gastrointestinal cancer, and gastrointestinal ulceration), hypomotility disorders (such as constipation, diabetic gastroparesis) and when used with medications known to potentiate these effects. During treatment with lanthanum carbonate, physicians and patients should remain vigilant for signs and symptoms of gastrointestinal disorders, especially constipation and abdominal pain/distention which may indicate bowel obstruction, ileus or subileus. Treatment with lanthanum carbonate should be re-evaluated in patients who develop severe constipation or other severe gastrointestinal signs and symptoms. Serious gastrointestinal complications have been reported in association with unchewed or incompletely chewed tablets. Conditions resulting in a marked reduction of bile flow may be associated with incrementally slower elimination of lanthanum, which may result in higher plasma levels and increased tissue deposition of lanthanum. Caution should therefore be exercised in these patients and monitoring of liver function may be required. Patients with renal insufficiency may develop hypocalcaemia. FOSRENOL does not contain calcium. Serum calcium levels should therefore be monitored at the regular time intervals for this patient population and appropriate supplements given.

Contraindications

Hypersensitivity to lanthanum or any of the excipients in the product. Bowel obstruction, ileus, and faecal impaction. Hypophosphataemia.

Regulatory history

FOSRENOL was first listed on the ARTG on 8 November 2005, with three strengths registered: 500 mg, 750 mg, and 1000 mg lanthanum chewable tablets. A submission by Shire Australia Pty Limited to extend the indications of FOSRENOL to include all patients with chronic kidney disease experiencing hyperphosphataemia was withdrawn with changes to the Product Information on 8 December 2011. Consequently, the approved indication for the treatment of hyperphosphataemia in adults with chronic renal failure on haemodialysis or continuous ambulatory peritoneal dialysis (CAPD) remained unchanged. Long-term clinical data up to 4.5 years demonstrated that bone lanthanum concentration had no apparent effect on bone health or treatment outcome. This evidence supported the removal of the previous 2-year restriction on the duration of administration.