Metabolic alkalosis due to absorption of “nonabsorbable” antacids

In a patient with end-stage renal disease undergoing long-term maintenance hemodialysis, moderately severe metabolic alkalosis developed in the absence of vomiting or gastric drainage. The cause of the acid-base disorder was exogenous alkali administration, in the form of combined ingestion of “nonabsorbable” antacids (aluminum hydroxide and magnesium hydroxide), neutral phosphate, and a cation-exchange resin (sodium polystyrene sulfonate). In this report, the relevant data of this patient are detailed, and the literature on this well-documented, albeit poorly recognized, acid-base derangement is summarized.