Comparison of lithium ratio between African-American and Caucasian bipolar patients

Lithium RBC/plasma ratio (LR) was studied in 34 bipolar subjects on therapeutic doses of lithium carbonate. The sample was divided into 22 Caucasians and 12 African-Americans to observe possible ethnic differences in LR as previously reported. The latter group demonstrated a higher LR as well as increased reports of side effects (p < .05), even after controlling previous confounding factors. Our findings suggest that African-Americans may be more susceptible to the side effects associated with lithium treatment, and consequently, lower dosages may be necessary for this group.