Reversible hypercalcemia and hyperparathyroidism associated with lithium therapy: case report and review of...

To present a case of reversible hypercalcemia and hyperparathyroidism associated with lithium therapy and to discuss the pathophysiology and management of this condition.

The clinical and laboratory findings in a patient with lithium-induced hypercalcemia are presented. A PubMed search for associated English language articles (with use of the key words lithium, hypercalcemia, and hyperparathyroidism) was conducted, and the relevant literature to date was reviewed. An approach to the management of patients with lithium-induced hypercalcemia is suggested.

A 56-year-old man was referred for management of incidentally discovered hypercalcemia. The serum parathyroid hormone (PTH) level was increased; serum phosphorus and 24-hour urine calcium excretion were both normal. For 5 years, he had been treated with lithium carbonate for bipolar affective disorder. The laboratory features were consistent with lithium-induced primary hyperparathyroidism. Discontinuation of lithium treatment resulted in normalization of serum calcium and PTH levels. Review of the literature suggests that hypercalcemia and hyperparathyroidism are common consequences of lithium therapy.

Hypercalcemia associated with lithium-induced hyperparathyroidism is a common, but underrecognized, complication of lithium therapy. Most patients have mild asymptomatic hypercalcemia. The long-term consequences of mild lithium-induced hypercalcemia are unknown. After discontinuation of lithium, the hypercalcemia may not always resolve; thus, parathyroidectomy may be necessary in some cases. Measurement of the serum calcium and PTH levels before and periodically after the initiation of lithium treatment is advisable. The appropriate monitoring of patients with lithium-induced hypercalcemia and decisions regarding parathyroidectomy are unclear. The decision to continue lithium therapy in the presence of hypercalcemia should be individualized.