Hypercalcemia and diabetes insipidus in a patient previously treated with lithium.

BACKGROUND: A 65-year-old woman presented with decreased oral intake, a reduced level of consciousness, hypercalcemia and hypernatremia. She had previously received lithium for 20 years for a schizoaffective disorder, but this treatment had been discontinued 3 years before presentation. INVESTIGATIONS: Physical examination, laboratory studies including measurement of serum calcium and parathyroid hormone levels, measurement of urine and serum osmolalities before and after desmopressin administration, blood and urine cultures, and a CT scan of the abdomen. DIAGNOSIS: Urosepsis, dehydration, kidney stone disease, hyperparathyroidism, and nephrogenic diabetes insipidus. MANAGEMENT: Hydration, antibiotics, intravenous pamidronate for rapid control of hypercalcemia, parathyroidectomy, surgical removal of the large kidney stones, a low-protein and low-sodium diet, and initiation of treatment with a thiazide diuretic.