Urinary excretion of albumin and transferrin in lithium maintenance treatment: daily versus alternate-day lithium dosing schedule

Urinary excretion of albumin and transferrin was determined by means of sensitive immunochemical methods in 40 manic-depressive patients prior to and following 6 months of daily or alternate-day lithium carbonate treatment. The median dose of lithium carbonate was 700 mg in the daily treatment group and 1200 mg in the alternate-day group, the corresponding median 12-h serum lithium concentration being 0.6 mmol l−1 and 0.7 mmol l−1, respectively. Urinary excretion of albumin and transferrin was significantly elevated in the lithium-treated patients as compared to a control group (Mann-Whitney). The change in urinary albumin: creatinine and transferrin: creatinine ratios between allocation and 6 months of treatment did not correlate significantly with the lithium dosing schedule (multiple linear regression), but did correlate with total lithium carbonate dose. In conclusion, the study provides no evidence of any difference in glomerular function (permeability) in the daily and alternate-day lithium dosing schedules, and lends no support to the hypothesis that alternate-day treatment diminishes the effect of lithium on renal function.