Accumulation of metals and minerals from phosphate binders

Abstract

Metals and minerals that depend on renal clearance may accumulate to toxic levels in patients with marginal kidney function. Toxicities of aluminum-based phosphate binders became apparent approximately 25 years ago. Nephrologists now recognize cardiovascular calcification may follow use of calcium-based phosphate binders. Five lessons can be learned: (1)safety must not be assumed in absence of data; (2) all evidence for causal linkage of toxicities from therapeutics must be considered, including animal data; (3) clinical trials are unlikely to reveal the spectrum of problems from long-term drug exposure; (4) complications can remain unrecognized until late in post-introduction surveillance; (5) minerals important for normal function can be toxic with excess accumulation. Introduction of new agents necessitates caution - it is difficult to change practice once a therapeutic is commonplace. Lessons learned about hazards of past phosphate binders must be applied judiciously when evaluating long-term risks/safety of novel metal-based binders such as lanthanum carbonate.