[Lithium treatment in patients with impaired kidney function: Between Scylla and Charybdis]

Introduction In quite a few patients with bipolar disorder there is no real alternative to lithium treatment despite impaired kidney function. Is it possible to continue lithium treatment despite kidney malfunction by changing dosage and/or frequency of administration? Case Report We report on a 65-year-old woman suffering from bipolar-I disorder who had been on lithium treatment for many decades. While on lithium, the glomerular filtration rate (GFR) decreased constantly. A decision had to be made whether to switch to a more tolerable o.d. administration or to taper off lithium. Conclusion With a single dose at bedtime, the serum levels remained stable; however, kidney function unfortunately did not improve. A relevant increase of GFR above the level of 60 mL/min/1,73 m² was only achieved after a 50% dose reduction leading also to a substantial decrease of lithium serum levels. A kidney protective lithium application in patients with reduced renal function is like sailing between Scylla and Charybdis.