Critical Care Medicine-Endocrine Disorders>>>>>Parathyroid and Calcium
Question 3#

Which of the following medications may mimic hyperparathyroidism?

A. Lithium
B. Haloperidol
C. Clozapine
D. Spironolactone

Correct Answer is A


Correct Answer: A

Lithium, primarily used as a psychiatric medication, can decrease parathyroid gland sensitivity to calcium, increasing serum levels of both calcium and PTH. It may also reduce urinary calcium excretion, further compounding its effect. Approximately 10% to 20% of patients taking lithium will develop hypercalcemia and hypocalciuria. Serum calcium concentration often returns to normal after discontinuation of lithium. Other serious side effects of lithium include hypothyroidism, diabetes insipidus, and lithium toxicity.


  1. Lehmann SW, Lee J. Lithium-associated hypercalcemia and hyperparathyroidism in the elderly: what do we know? J Affect Disord. 2013;146:151.
  2. Meehan AD, Udumyan R, Kardell M, et al. Lithium-associated hypercalcemia: pathophysiology, prevalence, management. World J Surg. 2018;42:415.