A Systematic Review Of Lanthanum Carbonate For Hyperparathyroidism In Dialysis Patients

Backgroud: Hyperphosphatemia develops in patients with end-stage renaldisease (ESRD) as a consequence of the inability to excrete phosphate by thekidney. Hyperphosphatemia is associated with reduced serum calcium levelsthat leads to secondary hyperparathyroidism and reanal bone disease.Moreover, hyperphosphatemia has been directly linked to increased mortalityand mobidity of cardiovascular disease in haemodialysis patients. Therefor, itis very important for end-stage renal disease patients to controlhyperphosphatemia. There is no sufficient effect to controlhyperphosphatemia by lowering dietary phosphate intake and removal ofphosphate by dialysis. So, patients usually have to use oral phosphate binders.Hyperphosphataemia has been treated using aluminium-and calcium-basedconventional phosphate-binding agents which may result to toxic effectsrelated to aluminum and hypercalcemia. Lanthanum carbonate is a potentnew, non-aluminium, non-calcium phosphate binder that has shown goodefficacy compared with other agents in some clinical human studies. There isno known systematic review of lanthanum carbonate treatment for hyperphosphatemia.Objective: To assess the efficacy and safety of Lanthanum Carbonate forhyperparathyroidism in dialysis patients.Method: According to the collaborative review group search strategy, wesearch MEDLINE (1996 to 2006.4); EMBASE(1996 to 2006.4); CochraneCentral Register of Controlled Trials (1st Quarter 2006); CBM disc; VIPand CNKI. We also handsearched the references of relevant studies.Randomized controlled trials (RCTs) comparing Lanthanum Carbonate withplacebo and standard therapy were eligible for inclusion. We search Chinesejournals by hand.We conducted quality assessment and data extraction bytow independent investigators. Meta-analysis was conducted by RevMan4.2.8. The following outcomes were assessed: serum phosphorus levels;serum PTH levels; calcium×phosphate product; serum calcium levels andserious adverse events. Results were expressed as OR with 95% confidenceinterval for dichotomous outcomes and WMD with 95% confidence intervalfor continuous outcomes.Results: We identified 7 reports which might meet the inclusion criteria forour review. Six trials were eligible for our study and one trial was excluded.Four short-term trials of lanthanum carbonate vs placebo met the inclusioncriteria. The meta-analysis showed that Lanthanum Carbonate was superioras placebo in treating hyperparathyroidism of dialysis patients (OR: 4.74;95%CI:2.66 to 8.45; P＜0.0001) and the incidence of total drug-relatedadverse events was similar between lanthanum carbonate- andplacebo-treated patients (OR: 1.23; 95%CI: 0.74 to 2.04; P=0.42). Towlong-term trials of lanthanum carbonate vs conventional phosphate binders met the inclusion criteria. The meta-analysis showed that the efficacy oftreating hyperparathyroidism of dialysis patients was similar betweenlanthanum carbonate and conventional phosphate binders (OR. 0.97; 95%CI: 0.74 to 1.27; P=0.81) and the incidence of total drag-related adverseevents was also similar. But, the serum calcium levels in the lanthanumcarbonate group were lower than conventional phosphate binders group.Conclusion: Lanthanum carbonate is well effective and tolerated in treatinghyperparathyroidism of dialysis patients with ESRD. The incidence ofhypercalcemia with lanthanum carbonate is significantly lower thanconventional phosphate binders. Further large randomized, double blind andlong course of treatment trials are needed in appreciating long-term safetyand efficacy of lanthanum carbonate.