Effect of calcium acetate/magnesium carbonate in the treatment of hyperphosphataemia in dialysis patients in real clinical practice. One year follow up.

Background: This observational study was conducted to investigate the use and effectiveness of calcium acetate/magnesium carbonate (CaMg) in the treatment of hyperphosphataemia in dialysis patients in real-world clinical practice. Methods: 120 adult CKD patients on dialysis who received CaMg alone or in combination with other phosphate binders were followed-up for 3-12 months. Serum phosphorus, calcium, magnesium, parathyroid hormone and albumin concentration was measured at baseline and after 3, 6 and 12 months respectively. In addition, CaMg dosage, use of concurrent phosphate binders, vitamin D and cinacalcet was documented. Patients were evaluated in 2 subgroups - CaMg alone (n=79) vs. CaMg + concurrent phosphate binder (n=41). Results: In both subgroups serum phosphorus levels decreased significantly from baseline at 3, 6 and 12 months of CaMg treatment. The percentage achievement of recommended serum phosphorus targets improved after CaMg initiation. At month 6, a total of 78% were within the Kidney Disease Outcomes Quality Initiative (K/DOQI) target range. Total corrected serum calcium increased during CaMg treatment, but mildly exceeded the upper limit of normal in three patients only. Asymptomatic significant increases in magnesium (p<0.001) were observed in the monotherapy group at 3, 6 and 12 months. A total of 80 patients (67%) experienced episodes of mild hypermagnesaemia (>2.6mg/mL, 1.05mmol/L). Conclusions: This analysis of current clinical practice shows that consistent with findings from a randomised controlled trial - CaMg treatment leads to marked improvement in serum phosphorus levels, helping patients in trying to achieve K/DOQI and KDIGO (Kidney Disease Improving Global Outcome) targets.