Hyperphosphatemia and nicotinic acid in peritoneal dialysis patients [2]

MUSSO, CARLOS GUIDO; REYNALDI, MARIA J.; APARICIO, CAROLINA; FRYDENLUND, SILVINA; IMPERIALI, NORA; ALGRANATI, L.

INTERNATIONAL UROLOGY AND NEFROLOGY

Springer

Año: 2008 vol. 40 p. 229 - 230

0301-1623

Dear Editor,Although hyperphosphatemia represents a serious problem in people on dialysis, an optimal treatment for this disorder has not been reported yet. It is known that the main source of phosphorus comes from the diet, and its absorption results from two combined processes: passive paracellular diffusion and luminal sodium-dependent transport against a concentration gradient [1, 2]. It has been reported that nicotinic acid, a B-complex vitamin, can reduce phosphorus absorption by inhibiting the activity of the above-mentioned intestinal sodium?phosphorus transporter [1, 3].Based on this previous information, we performed a protocol treating 18 hyperphosphatemic dialysis patients (three on haemodialysis and 15 on peritoneal dialysis) using a single dose (500 mg) of controlled-release nicotinic acid. These patients were on this vitamin treatment for 6 months, except for the ones on haemodialysis, in whom nicotinic acid had to be discontinued due to the appearance of severe episodes of flushing. This symptom, caused by vasodilatation, affected characteristically the upper part of their body: face, neck, and chest. Conversely, these episodes of flushing were practically absent in peritoneal dialysis patients. This difference in adverse reaction to nicotinic acid between the groups could be explained because only the peritoneal dialysis patients were on 200 mg of aspirin, a drug that can reduce the nicotinic-acid-induced flushing [1]. No other side effects secondary to this vitamin, such as thrombocytopenia, hepatic enzymes, or serum glucose elevation, were documented.After 6 months of treatment, we found no statistically significant difference between the initial serum phosphorus levels and postnicotinic treatment levels (Table 1). Thus, we concluded that, at least in our experience, a single dose (500 mg) of controlled-release nicotinic acid was not effective in reducing hyperphosphatemia in peritoneal dialysis patients.