Continuation of lithium after a diagnosis of chronic kidney disease Kessing LV, Feldt-Rasmussen B, Andersen PK, Gerds TA, Licht RW. Continuation of lithium after a diagnosis of chronic kidney disease. Objective: To investigate whether continued lithium or anticonvulsant treatment after a first diagnosis of chronic kidney disease (CKD) was associated with progression to irreversible end-stage kidney disease. Methods: Nationwide cohort study including all individuals in Denmark in a period from 1995 to 2012 with a diagnosis of CKD and (i) a history of lithium treatment (N = 754, among whom 238 patients had a diagnosis of bipolar disorder) or (ii) a history of anticonvulsant treatment (N = 5.004, among whom 199 patients had a diagnosis of bipolar disorder). End-stage CKD was defined as chronic dialysis or renal transplantation. Results: Continuing lithium (HR = 0.58 (95% CI: 0.37–0.90) and continuing anticonvulsants (HR = 0.53 (95% CI: 0.44–0.64) were associated with decreased rates of end-stage CKD. In the subcohorts of patients with a diagnosis of bipolar disorder, continuing lithium was associated with decreased end-stage CKD (HR = 0.40 (95% CI: 0.17–0.98), whereas continuing anticonvulsants was not (HR = 0.70 (95% CI: 0.21– 2.37). There were no interactions of continuing lithium and anticonvulsants. Conclusion: After an initial diagnosis of CKD, patients who are selected by their physicians to continue lithium treatment may not necessarily have an increased risk of developing end-stage CKD. Shifting to an anticonvulsant per se may not be associated with an advantage; however, this requires further investigation. L. V. Kessing 1 , B. Feldt-Rasmussen 2 , P. K. Andersen 3 , T. A. Gerds 3 , R. W. Licht 4,5 1 Psychiatric Center Copenhagen, University of Copenhagen, Copenhagen, Denmark, 2 Department of Nephrology, University of Copenhagen, Copenhagen, Denmark, 3 Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark, 4 Unit for Psychiatric Research, Aalborg University Hospital, Aalborg, Denmark and 5 Department of Clinical Medicine, Aalborg University, Aalborg, Denmark Key words: bipolar disorder; chronic kidney disease; lithium; anticonvulsants Lars Vedel Kessing, Psychiatric Center Copenhagen, Department O, 6233, Blegdamsvej 9, 2100 Copenhagen, Denmark and Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. E-mail: lars.vedel.kessing@regionh.dk Accepted for publication September 18, 2017 Significant outcomes • Treatment with lithium as practiced in modern care may be continued in a large proportion of patients after an initial diagnosis of chronic kidney disease provided careful monitoring of kidney function without increasing the risk of developing end-stage chronic kidney disease. • Shift to an anticonvulsant per se does not seem to be associated with any advantage. Limitations • The associations between continued use of medication and end-stage CKD may at least partly be attributed to bias and require further investigation controlling for additional covariates and using laboratory measurement of renal function. Introduction Lithium has for more than 60 years been the main mood-stabilising treatment for bipolar disorder, and the evidence for a prophylactic effect of lithium is strong. The potential side effects of lithium have always been an issue, and among these, the possible impact of long-term lithium treatment on renal function has given rise to con- siderable concern (1, 2). Results from the most recent and largest controlled studies suggest that use of lithium is associated with an approximately twofold increased risk of chronic kidney disease (CKD), although detection bias cannot be excluded in the studies (3–6). On the other hand, 1 Acta Psychiatr Scand 2017: 1–8 © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd All rights reserved DOI: 10.1111/acps.12820 ACTA PSYCHIATRICA SCANDINAVICA