Water, lithium and sodium: watch out for dangerous injuries

Nephrogenic diabetes insipidus due to the inability of the kidneys to concentrate urine is frequently observed during lithium therapy. Lithium concentrates into principal cells in collecting ducts in the kidney and downregulates aquaporin 2 expression, which reduces renal reabsorption of water. This disease is characterized by polyuria - polydipsia leading to intracellular dehydration and hypernatremia. Water deprivation test is performed to confirm insipidus diabetes. The desmopressin permits to distinguish nephrogenic from cranial insipidus diabetes. We report the case of a 64 years old women who presented with global dehydration and severe hypernatremia. Four years ago, she was hospitalized for nephrogenic diabetes insipidus related to a self-induced lithium intoxication. Persistent nephrogenic insipidus diabetes after cessation of lithium therapy are described in literature, and this hypothesis may be consistent with this case report.