Renal function and renal pathology in patients with lithium-induced impairment of renal concentrating ability.

Lithium-induced impairment of renal concentrating ability is regarded as a harmless side effect of lithium treatment. This report presents investigations of renal function and renal pathology in 13 patients with reduced renal concentrating ability arising during lithium treatment. The reduced concentrating ability parallels histological damage and is a sign of lithium-induced chronic nephropathy.