Lanthanum: a safe phosphate binder.

Area of Science:

• Nephrology
• Pharmacology
• Toxicology

Background:

• Elevated inorganic phosphate in dialysis patients contributes to cardiovascular mortality and vascular calcification.
• Traditional calcium-based phosphate binders and vitamin D may increase calcium-phosphate product, raising ectopic mineralization risks.
• Calcium-free phosphate binders offer an alternative to manage hyperphosphatemia without augmenting calcium load.

Purpose of the Study:

• To discuss the metabolism and effects of lanthanum carbonate, a calcium-free phosphate binder.
• To evaluate the safety profile of lanthanum carbonate in bone, liver, and brain.
• To compare lanthanum's effects with other metal cations like aluminum.

Main Methods:

• Review of clinical studies and preclinical data on lanthanum carbonate.
• Analysis of lanthanum's pharmacokinetic and toxicological profile.
• Investigation of lanthanum distribution and effects in target organs.

Main Results:

• Lanthanum carbonate effectively controls hyperphosphatemia without increasing patient calcium load.
• Clinical studies show no toxic effects of lanthanum carbonate up to four years.
• Lanthanum exhibits extremely low bioavailability; observed bone effects are due to phosphate depletion, not direct toxicity.
• The liver is the primary route of lanthanum excretion, localized in hepatocyte lysosomes.
• No lanthanum was detected in brain tissue.

Conclusions:

• Lanthanum carbonate is a safe and effective calcium-free phosphate binder for dialysis patients.
• Its low bioavailability and specific excretion pathway contribute to a favorable safety profile.
• Further research supports its use in managing renal failure-associated hyperphosphatemia.