PTH and hyperparathyroidism: Lithium can be associated with hypercalcemia more commonly than hyperparathyroidism (Lally et al. 2013) and can exacerbate preexisting hyperparathyroidism, increasing the rate of multiglandular disease; subtotal parathyroidectomy, intraoperative parathyroid hormone determination-guided excision, or the use of calcimimetics are the proposed treatment options (Szalat et al. 2009).