EFFECT OF DELAYED TREATMENT WITH SODIUM POLYSTYRENE SULFONATE ON SERUM LITHIUM CONCENTRATIONS IN MICE

Objectives: To determine the efficacy of sodium polystyrene sulfonate (SPS) in lowering serum lithium (Li) concentrations. Specifically, to determine the effects of both different doses of SPS and different tim es to treatment with SPS on serum Li levels. Methods: The study was a controlled, single-dose murine trial of SPS on serum Li levels. Male C D-1 mice (n = 525) were given orogastric LiCl and then divided into th ree main treatment groups: group SPS received a single orogastric admi nistration of SPS in a dose of 5 gm/kg body weight at either 0, 15, 30 , 45, or 90 minutes after LiCl; group half-SPS received a single oroga stric administration of SPS in a dose of 2.5 gm/kg body weight at time s equivalent to those of group SPS; and the control group received oro gastric deionized water in a volume equivalent to that of group SPS at 0, 15, 30, 45, or 90 minutes after LiCl. Subgroups of seven to ten mi ce in each of the four treatment groups were sacrificed at one, two, f our, and eight hours after administration of LiCl, and their blood was analyzed for Li concentration. Results: 1) Single doses of SPS signif icantly lowered serum Li concentrations; 2) this effect was dose-relat ed; 3) the delays in administration of SPS used in this study did not significantly reduce its ability to lower serum Li concentrations; and 4) even when administered after peak serum Li concentrations had been achieved, a single dose of SPS was effective in lowering serum Li lev els. Conclusions: SPS may be efficacious in the treatment for Li toxic ity under certain circumstances, even when there is delay to treatment . Additional study is warranted to further characterize the ability of SPS to alter Li kinetics.