A nurse is caring for a client who has a prescription for levothyroxine. Which of the following laboratory tests should the nurse monitor?

Explanation B.Triiodothyronine Levothyroxine is a synthetic form of the thyroid hormone thyroxine (T4). It is converted to triiodothyronine (T3), the active form of the thyroid hormone, in the body. Monitoring the levels of triiodothyronine (T3) can help assess the effectiveness of levothyroxine therapy and ensure that the client's thyroid hormone levels are within the desired therapeutic range. Serum potassium levels in (option A) should not be monitored because they are not directly affected by levothyroxine. However, imbalances in electrolytes can occur in some individuals with thyroid disorders. Electrolyte levels may be monitored, but it is not the primary focus of monitoring for levothyroxine therapy. Blood urea nitrogen (BUN) in (option C) should not be monitored because it is a test used to assess kidney function and is not directly related to monitoring levothyroxine therapy. Prothrombin time (PT) in (option D) should not be monitored because it is a test used to evaluate the clotting function of the blood and is not specifically related to monitoring levothyroxine therapy.