[Between efficiency and toxicity: the case of a patient improved by lithium who developed iatrogenic nephropathy]

Although almost fifteen cases have been reported since 1970, renal failure during a long term lithium therapy remains in the epidemiologic studies a rare pathology. Lithium treatment side effects can be considered in term of morphologic damages or in terms of kidney physiology impairments in filtration or concentration. For example it has long been known that lithium generates polyuria which results from an induced nephrotic diabetes insipidus (NDI). Fortunately most of these common impairments are reversible without any alarming or starting consequences. Moreover histological injures may also occur such as interstitial fibrosis, sclerotic glomeruli, tubular atrophy or dilatation ... whose evidence still raises some controversy concerning their incidence and specificity. We report here the case of a Bipolar I patient stabilized for at least fifteen years with lithium at a high level of social and professional life, in whom renal failure was found with tubular damage. This injury correlated to the lithium therapy even if always controlled at a normal rate during fifteen years, forced us to withdraw this treatment and switch to valproate. Is our goal to protect the renal function against the patient wishes totally justified since he relapsed in hypomania 63 days after the drop out? We had to choose between renal preservation and mental health.