[Is lanthanum carbonate a safe drug?]

Lanthanum carbonate is drawing attention as a new effective oral phosphate binder. This drug shares a character that "heavy metal that is not the natural constituent of human body and ionizes into free cations in gastrointestinal tract" with aluminum hydroxide gel. In fact, although the amount is much less than that of aluminum hydroxide gel, lanthanum is absorbed through intestine and accumulated in the body. Fortunately, there has been no report about the toxicity of such accumulated lanthanum. However, it does never mean that "lanthanum carbonate is harmless", since it usually takes years to demonstrate metal toxicity.