EFFECT OF SINGLE-DOSE RESIN-CATHARTIC THERAPY ON SERUM POTASSIUM CONCENTRATION IN PATIENTS WITH END-STAGE RENAL-DISEASE

Hyperkalemia in patients with renal failure is frequently treated with a cation exchange resin (sodium polystyrene sulfonate, hereafter refe rred to as resin) in combination with a cathartic, but the effect of s uch therapy on serum potassium concentration has not been established. This study evaluates the effect of four single-dose resin-cathartic r egimens and placebo on 5 different test days in six patients with chro nic renal failure. Dietary intake was controlled. Fecal potassium outp ut and serum potassium concentration were measured for 12 h. Phenolpht halein alone caused an average fecal potassium output of 54 mEq, The a ddition of resin caused an increase in insoluble potassium output but a decrease in soluble potassium output therefore, there was no signifi cant effect of resin on total potassium output. Sorbitol plus resin ca used less potassium output than phenolphthalein plus resin. On placebo therapy, the average serum potassium concentration increased slightly (0.4 mEq/L) during the 12-h experiment. This rise was apparently abro gated by some of the regimens that included resin; this may have been due in part to extracellular volume expansion caused by absorption of sodium released from resin. Phenolphthalein regimens were associated w ith a slight rise in serum potassium concentrations (similar to placeb o), this may have been due to extracellular volume contraction produce d by high volume and sodium-rich diarrhea and acidosis secondary to bi carbonate losses. None of the regimens reduced serum potassium concent rations, compared with baseline levels. Because single-dose resin-cath artic therapy produces no or only trivial reductions in serum potassiu m concentration, and because this therapy is unpleasant and occasional ly is associated with serious complications, this study questions the wisdom of its use in the management of acute hyperkalemic episodes.