Renal Function After Lithium Withdrawal

Lithium and the kidneys: Researchers analyzed the effects of withdrawal of chronic lithium therapy on renal function.

RESEARCH UPDATE

CASE VIGNETTE

“Ms James” is a 58-year-old Caucasian female with a history of bipolar disorder with psychotic features and borderline intellectual function. She has been treated with clozapine 400 mg qHS and lithium 300 mg BID for more than a decade, with good clinical response. Ms James has chronic kidney disease, with a current eGFR of 47 mL/min per 1.73 m2. The patient and her sister (primary caretaker) are well aware of the adverse effects of lithium on kidney function. However, Ms James has a history of exacerbation of psychosis, which required inpatient psychiatric hospitalization when lithium was discontinued in the past. Therefore, she and her sister have requested to continue therapy. If Ms James were to discontinue lithium for an extended period of time, what is the likely impact on her renal function?

Lithium is associated with risk of chronic kidney disease (CKD), with an estimated prevalence of 10% to 35%.1 Fortunately, only a small proportion of chronic lithium users (perhaps 0.5% to 1%) develop CKD stage 4 or 5 (requiring hemodialysis or transplant). Data on the effects of discontinuing lithium on renal function are sparse and conflicting, and they are based on small samples.2,3 However, a Danish cohort study found that continuing lithium after a diagnosis of CKD was not associated with increased risk of developing end-stage CKD.4 Therefore, an understanding of the effects of lithium discontinuation on renal function would be important for clinical decision-making.

The Current Study

Hoekstra and colleagues5 studied the trajectory of renal function after discontinuation of chronic lithium therapy. The authors investigated the laboratory database of the Antes Centre for Mental Health Care in Rotterdam, The Netherlands. They identified patients who stopped using lithium between 2000 and 2015. They included patients with at least 2 creatinine values before and 1 value after stopping lithium, from which eGFR was calculated. Another inclusion criterion was availability of eGFR from at least 6 months before and 6 months after lithium discontinuation. The authors also identified a subset of patients who discontinued lithium at an eGFR of ≤60 mL/min.

Data were analyzed using linear mixed models. A linear trend in eGFR before and after lithium discontinuation was modeled by a linear spline, with a single know at the point when lithium was stopped. The model was optimized using restricted maximum likelihood (REML). The difference in eGFR between patients with and without improvement in kidney function was compared using Student’s t-test.

The authors identified 43 patients with data on eGFR available before and after discontinuation of lithium, primarily for bipolar or schizoaffective disorder. The mean age was 43, and 53% were male. The mean duration of lithium therapy was 9.6 years. The most common reason for lithium discontinuation was side effects (37%), although decline in renal function was cited as the main reason for 14% of patients.

eGFR increased in 67% (29 of 43) of patients. On average, eGFR increased by 2.0 mL/min/year after discontinuation. In 8 patients (19%), eGFR continued to decline after discontinuation, but at a smaller rate. In the remaining 6 patients (14%), eGFR continued to decline as a similar or increased rate. Thirteen patients had an eGFR of ≤60 mL/min when lithium was discontinued. Among these patients, eGFR increased in 7 and continued to decline in 6 patients. Among the patients with a continued decline, their mean eGFR at discontinuation was 32 mL/min and they had used lithium for an average of 8.6 years. Among the patients with an increase, their mean eGFR at discontinuation was 46 mL/min and they had used lithium for an average of 5.8 years.

Study Conclusions

The authors concluded that eGFR improved after lithium discontinuation. Furthermore, the vast majority of patients with CKD stage 3 or more (eGFR of ≤60 mL/min) showed either increased eGFR or a decrease in the rate of decline after stopping lithium. Study strengths included a relatively larger sample size than previous studies. Limitations are the small sample size of patients with CKD at the time of lithium discontinuation. Findings were nevertheless consistent with previous studies that found a low risk of more severe CKD (stage 4 or 5) in this population.

The Bottom Line

In the majority of patients, lithium discontinuation results in improvement either in renal function or less rapid deterioration.

Dr Miller is a professor in the Department of Psychiatry and Health Behavior at Augusta University in Augusta, Georgia. He is on the Editorial Board and serves as the schizophrenia section chief for Psychiatric TimesTM. The author reports that he receives research support from Augusta University, the National Institute of Mental Health, and the Stanley Medical Research Institute.

References

1. Nielsen RE, Kessing LV, Nolen WA, Licht RW. Lithium and renal impairment: a review on a still hot topicPharmacopsychiatry. 2018;51(5):200-205.

2. Bendz H. Kidney function in a selected lithium population. a prospective, controlled, lithium-withdrawal studyActa Psychiatr Scand. 1985;72(5):451-463.

3. Bendz H, Sjödin I, Aurell M. Renal function on and off lithium in patients treated with lithium for 15 years or more. a controlled, prospective lithium-withdrawal studyNephrol Dial Transplant. 1996;11(3):457-460.

4. Kessing LV, Feldt-Rasmussen B, Andersen PK, et al. Continuation of lithium after a diagnosis of chronic kidney disease. Acta Psychiatr Scand. 2017;136(6):615-622.

5. Hoekstra R, Lekkerkerker MN, Kuijper TM, et al. Renal function after withdrawal of lithiumBipolar Disord. 2022;24(6):667-670.