A historical cohort study of kidney damage in long-term lithium patients: continued surveillance needed

Abstract

SummaryBackgroundInsufficient knowledge on the longitudinal fate of renal function in lithium patients incited this retrospective study of 149 patients.MethodMedical record review of a lithium cohort (N= 149), 8–12 years after an initial renal function study.ResultsTwenty-one patients had died, one from uremia probably not caused by lithium, and 42 had discontinued lithium. Reduced urinary concentrating capacity (Umax) or glomerular filtration rate (GFR) was not more frequent among deceased or off-lithium patients than among the 86 patients who were on lithium at follow-up. In 63 of the latter patients, Umax had been re-examined after the initial study, and GFR in 29 patients. Reduced Umax and GFR had become twice as common, and average Umax and GFR had decreased significantly. The reduction of GFR was associated with lithium treatment duration and age, and reduced Umax with treatment duration only.ConclusionsReduced renal function is not a major cause of treatment discontinuation but becomes increasingly common with treatment duration.