Lithium absorption prevented by sodium polystyrene sulfonate in volunteers.

Abstract

To determine if sodium polystyrene sulfonate prevents absorption of lithium in human beings. Prospective, crossover study. Healthy volunteers age 22 to 34 years (three women and three men). After an eight-hour fast, subjects ingested 0.5 mEq/kg (18.5 mg/kg) lithium carbonate. One hour later, they ingested either 857 mg/kg sodium polystyrene sulfonate in 4 mL water/g sodium polystyrene sulfonate (experimental) or an equal volume of water without sodium polystyrene sulfonate (control). Serum lithium levels were drawn zero, one, two, three, four, six, eight, ten, 12, and 24 hours after lithium ingestion. The sodium polystyrene sulfonate group had a smaller mean area under the serum concentration curve (11.6 +/- 1.0 mEq/L.hr versus 13.6 +/- 1.5 mEq/L.hr, P < .001) and lower mean highest measured lithium level (0.85 +/- 0.11 mEq/L versus 1.05 +/- 0.10 mEq/L, P < .05) compared with the control group. There was no significant difference in 24-hour urine lithium excretion or in serum sodium and potassium levels. Sodium polystyrene sulfonate administration decreased absorption of lithium after a lithium carbonate overdose. Sodium polystyrene sulfonate may be useful clinically for gastric decontamination after lithium overdoses.