Hyperparathyroidism in association with lithium therapy

Area of Science:

• Endocrinology
• Psychiatry
• Nephrology

Background:

• Lithium is a common treatment for bipolar disorder (manic-depressive psychosis).
• Normocalcemia is typically observed before initiating lithium therapy.
• Progressive hypercalcemia is a potential, though uncommon, adverse effect of long-term lithium use.

Observation:

• A patient on long-term lithium therapy developed progressive hypercalcemia.
• Elevated parathyroid hormone levels and a parathyroid adenoma were identified.
• Hypercalcemia occurred despite very low urinary calcium excretion, differing from typical hyperparathyroidism.

Findings:

• Lithium therapy can be associated with the development or unmasking of parathyroid adenoma.
• The pathogenesis of lithium-induced hypercalcemia may involve altered calcium handling.
• This case highlights a unique presentation of hypercalcemia with suppressed urinary calcium.

Implications:

• Routine monitoring of serum calcium is recommended before and during lithium treatment.
• Physicians should consider parathyroid adenoma in patients on lithium experiencing hypercalcemia.
• Early detection and management are crucial for patients susceptible to lithium-related endocrine disturbances.