Muller C et al. – Lanthanum therapy is an efficient therapy of hyperphosphoremia by chelating phosphore in the digestive tract. Lanthanum is a silvery white metallic element that belongs to group 3 of the periodic table. This drug is lightly absorbed and has low water solubility. It should be borne in mind that abdominal X–rays of patients taking lanthanum carbonate may have a radio–opaque appearance typical of imaging agents. This characteristic is suggested to confirm adherence of the patient by doing an abdominal X–ray.