HDCN Article Review/Hyperlink

Tan CC, Harden PN, Rodger RSC, Rowe PA, SPooner RJ, Junor BJR, Briggs JD

Ranitidine reduces phosphate binding in dialysis patients receiving calcium carbonate

Nephrol Dial Transplant (May) 11:851-853 1996

Fifteen dialysis (both PD and hemo) patients underwent a double blind crossover study to receive ranitidine or placebo. The end-point was to evaluate the effect of gastric pH on phosphorus levels. Each treatment period lasted 4 weeks. The elemental Ca intake in the form of calcium carbonate was 2 g with a range of 0.5-3.0. The P levels were higher during the ranitidine phase (5.5 v. 4.9 mg/dl). The Ca and PTH levels were not different. The authors conclude that ranitidine has a significant adverse effect on the phosphate binding of calcium carbonate in patients with renal failure.

Comment: By increasing gastric ph, ranitidine presumably decreases the solubility of calcium carbonate thereby inhibiting P binding. The overall difference in P levels was small but, in some patients quite large. An assessment of dietary P intake was not done and one cannot rule out increases in dietary P intake during the ranitidine phase. It would have been interesting for them to have also studied calcium acetate. (Jay Delmez, M.D., Washington University at St. Louis, MO)