Lithium-induced nephropathy; One medication with multiple side effects: a case report.

Background: Lithium carbonate is commonly used in the treatment of bipolar disorder. A spectrum of side effects is associated with lithium, including nephrogenic diabetes insipidus, renal tubular acidosis, chronic tubulointerstitial nephropathy, and minimal change disease. Although the former three adverse effects are well-known, minimal change disease is relatively rare.

Case Presentation: We herein report a case of lithium therapy-induced minimal change disease with concurrent chronic tubulointerstitial nephropathy. A 66-year old man with bipolar disorder treated by lithium for 20 years, presented to the hospital with anasarca and decreased urine output for 4 weeks. The medical history also included hyperlipidemia, hypertension, and benign prostatic hyperplasia. Further laboratory investigation revealed elevated serum lithium (2.17 mmol/L), potassium (6.0 mmol/L), and creatinine levels (2.92 mg/dL), nephrotic range proteinuria, and hypoalbuminemia. Lithium was discontinued and the patient was treated with intravenous fluids. He underwent a kidney biopsy, which showed findings consistent with minimal change disease with concurrent acute tubular injury and chronic tubulointerstitial nephropathy. The patient was subsequently treated with steroids in an outpatient setting. He did not respond to the treatment, and hemodialysis was started.

Conclusion: Based on the previously reported cases and review of literature, occurrence of lithium-associated minimal change nephropathy is rare. Patients with lithium-associated minimal change disease and acute tubular injury usually respond to discontinuation of lithium therapy and/or steroid treatment. In this case, minimal change nephropathy was steroid-resistant and kidney function of the patient reported here did not recover after 6-month follow-up. We postulated the underlying cause to be minimal change disease with chronic tubulointerstitial nephropathy due to long-term lithium use. This case provides an example of a rare side effect of lithium-induced minimal change nephropathy with chronic tubulointerstitial nephropathy in addition to its well-known complication of interstitial nephritis or diabetes insipidus. In our opinion, these patients likely have much worse clinical outcome.