ABSTRACT
The serum lithium concentration depends on the daily lithium intake and the renal elimination of lithium: lithium clearance. The lithium ion is filtered freely through the glomerular membrane and is reabsorbed in the proximal tubule to almost the same extent as sodium and water; only under special circumstances is some lithium reabsorbed in the distal nephron. Lithium clearance varies proportionally with and is usually 20-30% of the glomerular filtration rate. Lithium clearance is calculated as the daily dosage of lithium in millimoles divided by 1.44 and divided by the serum lithium concentration in millimoles per liter.
