For a patient with hyperparathyroidism and a serum calcium level of 13 mg/dL, which medication should the nurse prepare to administer?

In the context of hyperparathyroidism, the condition is characterized by elevated levels of parathyroid hormone (PTH), which leads to increased calcium levels in the blood, known as hypercalcemia. With a serum calcium level of 13 mg/dL, which is significantly above the normal range, it is essential to address this condition promptly.

Calcitonin is the appropriate medication in this scenario because it helps to lower serum calcium levels. This hormone, produced naturally in the body by the thyroid gland, works by inhibiting the activity of osteoclasts, the cells responsible for bone resorption, which in turn decreases the release of calcium from the bones into the bloodstream. Besides, calcitonin promotes renal excretion of calcium, further aiding in the reduction of serum calcium levels.

In contrast, calcium carbonate and vitamin D would increase calcium levels, which is contraindicated in the setting of hypercalcemia. Alendronate, primarily used for osteoporosis and certain conditions causing bone loss, would not be suitable as it can also contribute to increased calcium release from bone. Therefore, administering calcitonin is the most appropriate intervention to manage the elevated calcium levels in a patient with hyperparathyroidism.