Renal function and morphology in long-term lithium and combined lithium-neuroleptic treatment

Ten patients on long-term lithium therapy and ten on lithium and neuroleptics (combination therapy) were examined with renal biopsy and tests of renal function. Patients on combination therapy had more pronounced histopathological changes and lower concentrating capacity than patients on lithium alone. Patients on combination therapy had received a larger total dose of lithium and had had higher maximum serum lithium levels than patients on lithium alone. Patients with large daily urine volumes had a low concentrating capacity. There was a negative correlation between degree of histopathological lesions and urinary concentrating capacity. Estimation of urinary concentrating capacity seems to be of value for the assessment of renal lesions in lithium treatment.