Should impaired renal function be considered a contra-indication for starting lithium?

Abstract

Background

Caution is generally advised when starting lithium treatment in patients with impaired renal function. We aimed to study the risk of developing severe chronic kidney disease (CKD) among patients with impaired renal function treated with lithium.

Methods

The risk of developing severe CKD was calculated from a register-based cohort of 83 cases with already elevated serum creatinine at lithium start compared to 83 controls matched by age, gender and duration of lithium treatment, with normal serum creatinine at lithium start. The definition of severe CKD was reaching at least stage 4 i.e. an estimated glomerular filtration rate (eGFR) of <30 ml/min/m². The data was collected from Sahlgrenska University Hospital's laboratory database and patient charts.

Results

The rate of severe CKD at 10-years follow-up was 48% (95%-confidence interval (95%-CI): 34–59%) for the cases and 11% (95%-CI: 2–18%) for the controls. Age and sex-adjusted Hazard Ratio was 6.7 for the whole follow-up (95%-CI 3.1–14.3, p < 0.001), considering the competing risk of death. The progression towards severe CKD was continuous over 20 years. Higher age at start of lithium, burden of somatic comorbidities and use of lithium before 1980 were associated with progression to severe CKD among cases.

Conclusions

Impaired renal function prior to initiating lithium treatment increases substantially the risk of developing severe CKD. Careful consideration of the benefits and risks of lithium therapy is strongly recommended. In patients with laboratory signs of renal impairment and prophylactic lithium treatment, associated somatic comorbidities should be closely monitored.