Lithium-induced hypercalcemia with normal parathyroid hormone: A case report.

Area of Science:

• Endocrinology
• Psychopharmacology

Background:

• Long-term lithium therapy is associated with hypercalcemia, often secondary to parathyroid gland dysfunction.
• Lithium-induced hypercalcemia typically presents with elevated parathyroid hormone (PTH) levels.

Observation:

• A 54-year-old male on intermittent lithium therapy for over a decade presented with hypercalcemia.
• The patient exhibited normal PTH concentrations during the hypercalcemic episode.
• No other identifiable cause for the hypercalcemia was found.

Findings:

• The Naranjo algorithm indicated lithium as the probable cause of hypercalcemia.
• This case presents a unique instance of lithium-induced hypercalcemia without concurrent hyperparathyroidism.

Implications:

• This case challenges the established understanding of lithium-induced hypercalcemia pathophysiology.
• Further research is warranted to explore potential non-parathyroid mechanisms underlying lithium's effect on calcium homeostasis.