Heavy metal--rely on gut feelings: novel diagnostic approach to test drug compliance in patients with lanthanum intake

Abstract

Keywords: calcification; drug compliance; lanthanumcarbonate; phosphate binder; X-rayAccording to several guidelines, a high calcium–phosphate product (>4.46mmol/l) is a majorcause of cardiovascular morbidity and mortality inpatients with end-stage renal disease (ESRD) [1].Hyperphosphataemia management is therapeuticallytedious, largely because of the number of tabletspatients must ingest. Monitoring compliance to ananti-phosphataemic regimen is bereft of reliable signs.Patients regularly swear faithful adherence to the hatedregimen, while their laboratory values suggest other-wise. A reliable indicator of compliance has not beenavailable until now. Serendipity served us a solution tothis knotty problem. Lanthanum carbonate is a novelcompound prescribed for phosphate binding in ESRDpatients. The drug is calcium-and aluminum-free.Prandial intake of lanthanum carbonate is generallywell tolerated. Lanthanum is poorly absorbed systemi-cally and therefore does not accumulate [2].The material appears to be non-toxic. Extensiveanimal studies have been performed and humanexperience thus far supports this contention [3].We report a 46-year-old woman who developedESRD after failing to recover from haemolytic uraemicsyndrome. She had undergone renal transplantation,which failed because of polyoma virus infection.Haemodialysis treatments were conducted accordingto guidelines, three times weekly. Her serum calciumranged at 2.4–2.6mmol/l and her phosphate waselevated at 2.28mmol/l (product 5.7mmol