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