Use of sodium polystyrene sulfonate in a lithium overdose.

A 23-year-old woman with an acute-on-chronic lithium overdose received multiple oral doses of sodium polystyrene sulfonate totaling 150 g over a 24-hour period. During the 33 hours after the institution of therapy, the serum lithium level decreased from 4.20 to 0.68 mEq/L. The calculated serum lithium elimination half-life of 12 hours is significantly shorter than that previously noted in other similar overdoses, and the patient suffered no adverse effects of therapy. Multiple-dose sodium polystyrene sulfonate may be useful in lowering the serum lithium level of select patients with acute lithium overdoses but is not a substitute for hemodialysis in severely ill patients.