Lanthanum carbonate is an effective hypophosphatemic agent for hemodialysis patients intolerant of other phosphate binders.

BACKGROUND: Lanthanum carbonate (LC) is a noncalcium-containing phosphate binder of proven utility in treating hyperphosphatemia in dialysis patients, and displays a good tolerability profile. OBJECTIVE: This study addressed whether this tolerability profile could result in improved phosphate control in patients intolerant of other phosphate binders, and who remain hyperphosphatemic despite intensive dietary advice and adequate dialysis provision. DESIGN, SETTING, AND PATIENTS: This 18-month study, from a large urban hemodialysis unit, studied 55 patients identified by the multidisciplinary team as fulfilling the following criteria: persistent hyperphosphatemia; intolerance of, or admitted nonadherence to, prescribed phosphate binders (either calcium-based or sevelamer); and provision of adequate dialysis (urea reduction ratio, >65%). INTERVENTION AND MAIN OUTCOME MEASURE: LC was substituted for existing phosphate binders, and results were compared between baseline and 3 months after the initiation of LC. RESULTS: A significant fall in phosphate level from 2.28+/-0.55mmol/L to 1.89+/-0.45mmol/L (7.06+/-1.70mg/dL to 5.85+/-1.39mg/dL) was evident 3 months after the medication switch (P < .001). This fall was associated with a significant increase in the number of patients achieving United Kingdom Renal Association guidelines for serum phosphate level (17% to 48%; P=.001). Mean phosphate-binder pill burden fell significantly by 3 months after the initiation of LC, from 7.8+/-3.4 tablets daily to 3.6+/-2.3 tablets daily. A small but significant increase also occurred in serum bicarbonate levels, from 23.3+/-2.2mmol/L (23.3+/-2.2 mEq/L) at baseline to 23.9+/-2.5mmol/L (23.9+/-2.5 mEq/L) at 3 months (P=.03). This was observed despite a prescribed reduction in dialysate bicarbonate concentration across the population (P=.03). CONCLUSION: This study demonstrated the utility of LC in hemodialysis patients intolerant of alternative phosphate binders, and suggests an advantage of this agent in this patient group.

A prospective study of combination therapy for hyperphosphataemia with calcium-containing phosphate binders and sevelamer in hypercalcaemic haemodialysis patients.

INTRODUCTION: Hyperphosphataemia is predictive of death, in haemodialysis (HD) patients. Sevelamer is a mineral-free phosphate binder not limited by the hypercalcaemia often encountered when utilizing calcium-containing phosphate binders. Highly positive calcium balance is associated with ectopic calcification and potentially accelerated vascular disease. Unfortunately, exclusive use of sevelamer entails a large cost differential, limiting its use in many centres. We report on a strategy of partial replacement of calcium with sevelamer for the management of hyperphosphataemia in hypercalcaemic chronic HD patients. METHODS: We identified 23 HD patients with serum calcium >2.6 mmol/l. Dietary phosphate and calcium intake were assessed and baseline serum calcium, phosphate and 1alpha calcidol and elemental calcium dose recorded. Fifty per cent of this initial calcium dose was exchanged for sevelamer. Vitamin D doses were left unchanged. If serum calcium was still >2.6 mmol/l after 4 weeks a further 50% of calcium was exchanged. If serum phosphate was >2 mmol/l the sevelamer dose was increased by 25%. The patients were followed up for a further 4 weeks. RESULTS: Seven patients complained of gastrointestinal intolerance of sevelamer. Serum calcium fell from a mean value of 2.8+/-0.04 (2.64-3.54) mmol/l to 2.56+/-0.03 (2.4-2.9) mmol/l, P<0.0005. The hypercalcaemic percentage of patients fell from 100 to 26%. Mean serum phosphate was not significantly changed, 1.59+/-0.1 (0.57-2.6) mmol/l to 1.63+/-0.11 (0.55-2.68) mmol/l, 17-22% of patients having serum phosphate >2 mmol/l. Serum intact parathyroid hormone increased from 166+/-47 (12-933) ng/l to 276+/-104 (20-1013) ng/l, P=0.02. Mean sevelamer dose was 2.77+/-0.36 (0-5.6) g per day. Elemental calcium dose fell from 2.05+/-0.23 (0.5-4.5) g to 1.03+/-0.1 (0.5-2.5) g, P<0.0001. CONCLUSION: A regimen based on the combination of sevelamer and calcium is capable of effectively managing hyperphosphataemia, without hypercalcaemia, in the majority of hypercalcaemic HD patients. Such a minimally calcaemic approach might reduce the financial burden of sevelamer therapy, and enable a wider range of patients to be treated.