Renal effects of long-term lithium therapy in the elderly: a cross-sectional study

✍ Scribed by Els J. M. van Melick; Arend E. Meinders; Tonko O. Hoffman; Toine C. G. Egberts

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 92 KB
• Volume: 23
• Category: Article
• ISSN: 0885-6230
• DOI: 10.1002/gps.1961

✦ Synopsis

Abstract

Objectives

To determine the effect of long‐term lithium therapy on glomerular filtration rate (GFR) and maximum renal concentrating capacity (Umax) in the elderly, to identify possible risk factors, to determine the clinical impact of a reduced Umax in this population and in case of polyuria to establish a diagnosis.

Methods

This is a cross‐sectional study with 48 outpatients of 65 years or over (mean 74.8 years), who were treated with lithium for more than 6 months (mean 9.2 years). The GFR was determined with the Cockcroft‐Gault formula (GFR‐CG) and the Umax was measured in a urine sample collected between 3 and 5 h after the patients received 40 μg desmopressin (DDAVP) intranasally.

Results

No relation was found between duration of lithium treatment and GFR‐CG, but there was a significant negative relation between duration of lithium treatment and Umax (B −0.73; CI: −1.249/−0.212); 73% of the patients had a moderate to severe concentrating defect. No other risk factors than duration of lithium therapy were identified. A reduced Umax caused polyuria (>2500 mL/24 h) in 33% but did not cause significant more thirst, incontinence or disturbed sleep.

Conclusions

In this geriatric population a negative relation was found between duration of lithium treatment and Umax. But a reduced Umax did not result in significant more clinical symptoms. In case of polyuria other mechanisms beside nephrogenic diabetes insipidus were found to play a role in this age group. Copyright © 2008 John Wiley & Sons, Ltd.