Use of nicotinamide to treat hyperphosphatemia in dialysis patients.

Hyperphosphatemia in chronic kidney disease (CKD) has been associated with elevated cardiovascular morbidity and mortality. Serum phosphate control remains a cornerstone of the clinical management of patients with CKD, in order to both attenuate the progression of secondary hyperparathyroidism or bone disease and (possibly) reduce the risk of vascular calcification. Despite technical improvements in dialysis and the use of dietary restrictions, drug therapy is often required to control phosphate levels in patients with end-stage renal disease (ESRD). Currently available medications for hyperphosphatemia in ESRD are very expensive and not always well tolerated. The discovery and development of new drugs in this indication is therefore a priority for both medical and health-economic reasons. Nicotinamide (an amide derivative of the water-soluble vitamin B3) is a potentially interesting alternative to phosphate binders. In vitro and in vivo data show that nicotinamide reduces hyperphosphatemia by inhibiting sodium-dependent phosphate co-transport in the renal proximal tubule and in the intestine. Accordingly, targeting the sodium-dependent phosphate co-transporter 2b by using nicotinamide as an alternative or adjunct to classical phosphate binders may be a therapeutic option for modulating serum phosphate in CKD. Several recent clinical studies have explored the potential value of nicotinamide in phosphate control (as well as its effects on lipid levels) in dialysis patients. However, we consider that more data on pharmacodynamics, pharmacokinetics and safety are needed before this compound can be recommended as a treatment for hyperphosphatemia in ESRD patients.