Lanthanum Carbonate Chewable Tablets

FOSRENOL is  phosphate binder indicated to reduce serum phosphate in patients with end stage renal disease (ESRD).

Management of elevated serum phosphorous levels in end stage renal disease patients 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.

The symptoms associated with overdose are adverse reactions such as headache, nausea and vomiting. In clinical trials in healthy adults, GI symptoms were reported with daily doses up to 6000 mg/day of lanthanum carbonate administered with food. Given the topical activity of lanthanum in the gut, and the excretion in feces of the majority of the dose, supportive therapy is recommended for overdosage. Lanthanum carbonate was not acutely toxic in animals by the oral route. No deaths and no adverse effects occurred in mice, rats or dogs after single oral doses of 2000 mg/kg (1.7, 3.4, and 11.3 times the MRHD, respectively, on a mg/m² basis).

Overall, the safety profile of FOSRENOL has been studied in over 5200 subjects in completed clinical trials. The most common adverse reactions for FOSRENOL were gastrointestinal events, such as nausea, vomiting, and abdominal pain and they generally abated over time with continued dosing.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In double-blind, placebo-controlled studies where a total of 180 and 95 ESRD patientswere randomized to FOSRENOL chewable tablet and placebo, respectively, for 4-6 weeks of treatment, the most common reactions that were more frequent ( ≥ 5% difference) in the FOSRENOL group were nausea, vomiting, and abdominal pain (Table 1).

Table 1: Adverse Reactions* That Were More Common on FOSRENOL in Placebo- Controlled, Double-Blind Studies With Treatment Periods of 4-6 Weeks

In an open-label long-term 2 year extension study in 93 patients who had transitioned from other studies, resulting in a total of up to 6 years treatment, mean baseline values and changes in transaminases were similar to those observed in the earlier comparative studies, with little change during treatment.

The safety of FOSRENOL was studied in two long-term, open-labeled clinical trials, which included 1215 patients treated with FOSRENOL and 944 with alternative therapy. Fourteen percent (14%) of FOSRENOL treated patients discontinued treatment due to adverse events. Gastrointestinal adverse reactions, such as nausea, diarrhea and vomiting were the most common types of event leading to discontinuation.

In pooled active comparator controlled clinical trials, hypocalcemia was noted with an incidence of approximately 5% in both lanthanum and active comparator groups. A nonclinical study and a phase 1 study have shown reduced absorption of calcium in the intestine with lanthanum carbonate treatment.

In a crossover study in 72 healthy individuals comparing Fosrenol chewable tablets to Fosrenol oral powder, gastrointestinal adverse reactions such as nausea, diarrhea and vomiting were more common for the oral powder formulation (18%) than for the chewable tablets (7%).

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of FOSRENOL. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: constipation, dyspepsia, allergic skin reactions, hypophosphatemia, and tooth injury while chewing the tablet.

Read the entire FDA prescribing information for Fosrenol (Lanthanum Carbonate Chewable Tablets)

• Kidney Failure