REFOS study: efficacy and safety of lanthanum carbonate in clinical practice in Spain.

Lanthanum carbonate is a powerful phosphate binder that has shown efficacy and safety in clinical trials for hyperphosphataemia management, although there are few data in regular clinical practice. The study's objective was to evaluate, in regular clinical practice, its efficacy and safety in patients on dialysis. We retrospectively collected data from 15 months of monitoring, corresponding to 3 months prior to the start of treatment with lanthanum carbonate until 12 months after the start. Results included values of serum calcium, phosphorus, alkaline phosphatase, iPTH, hepatic enzymes and haemogram, as well as the daily-prescribed dose of lanthanum carbonate, the concomitant medication, treatment compliance and adverse events. 647 patients were included of which 522 completed the study. Abandonment, for the most part, was due to gastrointestinal disorders (26%) and hypophosphatemia (19%). Serum phosphorus decreased from 6.4±1.7 mg/dl (start) to 4.9±1.4 mg/dl (12 months) (P<.001). At the end of the monitoring period, 47% were within the desired phosphorus range (3.5-5mg/dl). There were no significant variations in the remaining parameters. Initial dose of lanthanum carbonate: 1900 mg/day; and end dose: 2300 mg/day. The variables independently associated with phosphataemia were baseline serum phosphorus and treatment compliance. In relation to safety, we observed 238 slight or moderate adverse effects in 117 patients, with 88% linked to gastrointestinal abnormalities. In conclusion, lanthanum carbonate reduces the serum phosphorus values in patients on dialysis with a good safety profile and acceptable adherence to that profile, with gastrointestinal disorders being the most frequent adverse effect.