Symptomatic hypocalcemia from oral sodium phosphate: a report of two cases.

The use of oral sodium phosphate has, only in very rare instances (seven cases in the literature), been recognized to cause symptomatic hypocalcemia. We report a case in an elderly woman that led to severe tetany and a 10-day admission to control the electrolyte disturbances. The patient was predisposed to developing this complication because of chronic renal failure and vitamin D deficiency. The second hypocalcemic patient had perioral tingling and numbness of the extremities but recovered quickly because of normal renal function. Magnesium depletion was a predisposing factor in the second case. These cases illustrate the rising prevalence of this disorder, which can have severe consequences and can be prevented by avoiding the prescription of these agents to high risk patient groups.