Results of clinical renal function tests in lithium patients.

Because there have been reports suggesting that patients who receive lithium are at risk for renal damage, the authors carried out extensive noninvasive testing of renal function in 43 patients who had been taking lithium for from 1 to 120 months. Their only abnormal finding was that the urine concentrating ability of these patients was moderately but asymptomatically impaired. They suggest that although patients receiving lithium should be carefully evaluated and tested, there is not enough evidence to justify not initiating or continuing lithium use in patients who might benefit from it.