FOSRENOL contains lanthanum carbonate with molecular formula La 2 (CO 3 ) 3 xH 2 O (on average x=4-5 moles of water) and molecular weight 457.8 (anhydrous mass). Lanthanum carbonate is described as white to almost-white powder. Lanthanum carbonate is practically insoluble in water and is insoluble in organic solvents; it dissolves in dilute mineral acids with effervescence. Each FOSRENOL, white to off-white, chewable tablet contains lanthanum carbonate hydrate equivalent to 500, 750, or 1,000 mg of elemental lanthanum and the following inactive ingredients: colloidal silicon dioxide, dextrates (hydrated), magnesium stearate. FOSRENOL Oral Powder is a white to off-white powder containing lanthanum carbonate hydrate equivalent to 750 or 1,000 mg of elemental lanthanum and the following inactive ingredients: colloidal silicon dioxide, dextrates (hydrated), magnesium stearate.

FOSRENOL ® is a phosphate binder indicated to reduce serum phosphate in patients with end-stage renal disease (ESRD). Management of elevated serum phosphorus levels in patients with ESRD usually includes all of the following: reduction in dietary intake of phosphate, removal of phosphate by dialysis, and reduction of intestinal phosphate absorption with phosphate binders. FOSRENOL is a phosphate binder indicated to reduce serum phosphate in patients with end-stage renal disease (ESRD).

FOSRENOL Chewable Tablets: 500 mg, 750 mg, and 1,000 mg. FOSRENOL Oral Powder: 750 mg and 1,000 mg. FOSRENOL Chewable Tablets: 500 mg, 750 mg, and 1,000 mg. FOSRENOL Oral Powder: 750 mg and 1,000 mg.

Divide the total daily dose of FOSRENOL and take with or immediately after meals. The recommended initial total daily dose of FOSRENOL is 1,500 mg. Titrate the dose every 2 to 3 weeks until an acceptable serum phosphate level is reached. Monitor serum phosphate levels as needed during dose titration and on a regular basis thereafter. FOSRENOL has the potential to bind other orally administered drugs; consider separating the administration of other oral medications . In clinical studies of patients with ESRD, FOSRENOL doses up to 4,500 mg were evaluated. Most patients required a total daily dose between 1,500 mg and 3,000 mg to reduce plasma phosphate levels to less than 6.0 mg/dL. Doses were generally titrated in increments of 750 mg/day. The recommended initial total daily dose of FOSRENOL is 1,500 mg in divided doses. Titrate every 2 to 3 weeks based on serum phosphate level. Take FOSRENOL with or immediately after meals. FOSRENOL Chewable Tablets: Chew or crush tablet completely before swallowing. FOSRENOL Oral Powder: Sprinkle powder on a small quantity of applesauce or other similar food and consume immediately. Consider powder formulation in patients with poor dentition or who have difficulty chewing tablets. Information for FOSRENOL Chewable Tablets Chew or crush FOSRENOL Chewable Tablets completely before swallowing. Do not swallow intact FOSRENOL Chewable Tablets. Information for FOSRENOL Oral Powder Sprinkle FOSRENOL Oral Powder on a small quantity of applesauce or other similar food and consume immediately. Do not open until ready to use. Do not store FOSRENOL Oral Powder for future use once mixed with food. Because FOSRENOL Oral Powder is insoluble, do not attempt to dissolve in liquid for administration. Consider using the oral powder formulation in patients with poor dentition or who have difficulty chewing tablets.

Serious cases of gastrointestinal obstruction, ileus, subileus, gastrointestinal perforation, and fecal impaction. Risks include altered gastrointestinal anatomy, hypomotility disorders, and concomitant medications. Advise patients to chew or crush the tablet completely. FOSRENOL has radio-opaque properties and, therefore, may give the appearance typical of an imaging agent during abdominal X-ray procedures. 5.1 Gastrointestinal Adverse Effects Serious cases of gastrointestinal obstruction, ileus, subileus, gastrointestinal perforation, and fecal impaction have been reported in patients taking lanthanum, some requiring surgery or hospitalization. Consider discontinuing FOSRENOL in patients without another explanation for severe gastrointestinal symptoms. Risk factors for gastrointestinal obstruction and gastrointestinal perforation identified from post-marketing reports in patients taking FOSRENOL Chewable Tablets include abnormal gastrointestinal anatomy (e.g., diverticular disease, peritonitis, history of gastrointestinal surgery, gastrointestinal cancer, gastrointestinal ulceration), hypomotility disorders (e.g., constipation, ileus, subileus, diabetic gastroparesis), and the use of medications known to potentiate these effects. Some cases were reported in patients with no history of gastrointestinal disease. Patients with acute peptic ulcer, ulcerative colitis, Crohn's disease, or bowel obstruction were not included in FOSRENOL clinical studies . Advise patients who are prescribed FOSRENOL Chewable Tablets to chew the tablet completely and not to swallow them whole. Serious gastrointestinal complications have been reported in association with unchewed or incompletely chewed tablets

Diagnostic Tests FOSRENOL has radio-opaque properties and therefore may give the appearance typical of an imaging agent during abdominal X-ray procedures. Postmarketing reports of product residue have been reported during endoscopic imaging.

There is a potential for FOSRENOL to interact with compounds that bind to cationic antacids (i.e., aluminum-, magnesium-, or calcium-based); therefore, do not take such compounds within 2 hours of dosing with FOSRENOL. Oral quinolone antibiotics must be taken at least 1 hour before or 4 hours after FOSRENOL. Do not take thyroid hormone replacement therapy within 2 hours of dosing with FOSRENOL. Monitoring of TSH levels is recommended in patients receiving both medicinal agents. For oral medications where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy, consider separation of the timing of the administration of the two drugs

Drugs Binding to Antacids There is a potential for FOSRENOL to interact with compounds which bind to cationic antacids (i.e., aluminum-, magnesium-, or calcium-based); therefore, do not administer such compounds within 2 hours of dosing with FOSRENOL. Examples of relevant classes of compounds where antacids have been demonstrated to reduce bioavailability include antibiotics (such as quinolones, ampicillin, and tetracyclines), thyroid hormones, ACE inhibitors, statin lipid regulators, and anti-malarials

Quinolone Antibiotics Co-administration of FOSRENOL with quinolone antibiotics may reduce the extent of their absorption. The bioavailability of oral ciprofloxacin was decreased by approximately 50% when taken with FOSRENOL in a single-dose study in healthy volunteers. Administer oral quinolone antibiotics at least 1 hour before or 4 hours after FOSRENOL. When oral quinolones are given for short courses, consider eliminating the doses of FOSRENOL that would normally be scheduled near the time of quinolone intake to improve quinolone absorption

Levothyroxine The bioavailability of levothyroxine was decreased by approximately 40% when taken together with FOSRENOL. Administer thyroid hormone replacement therapy at least 2 hours before or 2 hours after dosing with FOSRENOL and monitor thyroid stimulating hormone (TSH) levels

Use with Other Oral Medications There are no empirical data on avoiding drug interactions between FOSRENOL and most concomitant oral drugs. For oral medications where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy, consider separation of the timing of the administration of the two drugs. The duration of separation depends upon the absorption characteristics of the medication concomitantly administered, such as the time to reach peak systemic levels and whether the drug is an immediate-release or an extended-release product. Consider monitoring clinical responses or blood levels of concomitant medications that have a narrow therapeutic range.