Lithium Carbonate Orally Increases Renal Sodium Excretion

We studied the effect of 600 mg lithium carbonate on renal sodium excretion. Nine healthy volunteers, aged 25-40 years, were investigated during 3 days. Their urine was collected at 10 p.m., 7 a.m., 1 p.m. and 4 p.m. Blood samples were drawn every morning at 10 a.m. Lithium carbonate was given at 10 p.m. before the start of the 2nd day. Urine collections were measured for volume, sodium and creatinine. Blood samples were investigated for lithium, sodium and creatinine. Fractional sodium excretion (FE Na ) was calculated