Which two key electrolytes should be monitored when a patient is taking lithium?

The correct answer focuses on calcium and sodium, which are critical electrolytes to monitor in patients undergoing lithium therapy.

Lithium, a mood stabilizer often used in the treatment of bipolar disorder, can affect electrolyte balance significantly. Sodium is particularly important because lithium and sodium share similarities in their renal handling. When sodium levels are low, the kidneys may retain lithium to conserve sodium, which can lead to increased lithium levels in the body and potential toxicity. Therefore, maintaining proper sodium levels is crucial for safe lithium administration.

Calcium also plays a vital role, particularly as lithium can impact calcium metabolism and the function of parathyroid hormone, leading to potential disturbances such as hypercalcemia in some patients. Monitoring calcium helps in assessing bodily functions and potential side effects related to lithium therapy.

The other choices, while they include important electrolytes, do not directly relate to the specific concerns associated with lithium treatment in the same way that sodium and calcium do. Potassium and magnesium, although important in overall health, are not typically the primary focus when managing patients on lithium.