Endocrine Abstracts

Introduction: Lithium is the preferred and most efficacious therapy for acute and maintenance therapy of bipolar depressive disorder. Lithium use is associated with an increased incidence of hyperparathyroidism (4.3–6.3%) and have a female preponderance. Bilateral neck exploration was the most common surgical approach while a few patients were managed medically. The initial management of Lithium-associated hyperparathyroidism (LAH) is medical intervention which includes discontinuation of lithium or use of an alternative treatment such as atypical antipsychotics and calcimimetics. Here we demonstrate improved psychiatric symptoms after cessation of lithium and successful treatment of hypercalcemia by cinacalcet in a geriatric patient with LAH.

Case: 81-year-old woman with a history of bipolar disorder treated with lithium carbonate for more than 10 years presented with nocturia and polyuria. Her serum calcium was 11.58 mg/dl (Normal – 9–10.5 mg/dl), alkaline phosphatase 175 U/L (Normal – 30–120 U/l)), serum parathyroid hormone 380 pg/ml (Normal – 10–60 pg/ml) and phosphorus 2.1 mg/dl (normal 3–4.5 mg/dl). No definite parathyroid lesions were identified by neck ultrasonography and Sestamibi/ SPECT scans. Lithium treatment was stopped after consultation with psychiatrist. More than 3 months later, she had persistent hypercalcemia and depressive symtomps recurred. Cinacalcet (30 mg once daily) was started. After 2 weeks of treatment serum calcium level decreased to 9.5 mg/dl and PTH level was 160 pg/ml.Cinacalcet was well tolerated and the patient’s psychiatric symptoms improved without any need for lithium or other antidepressant drug.

Conclusion: Cinacalcet is known to be effective in primary hyperparathyroidism but our observations also support the use of this calcimimetic agent in lithium-induced hyperparathyroidism as a potential alternative to surgery in geriatric patients. Treatment of hypercalcemia might help to resolve depressive symptoms in these patients. Cinacalcet could represent an important pharmacological intervention in MEN1-associated primary hyperparathyroidism before surgery and in postsurgical recurrences.