After starting treatment for type 2 diabetes mellitus 6 months earlier, a patient is in the office for a follow-up examination. The nurse will monitor which laboratory test to evaluate the patient's adherence to the antidiabetic therapy over the past few months?

Choice A reason: This is incorrect because alopecia is not a common or serious adverse effect of finasteride. However, the patient should be informed that finasteride may cause decreased hair growth or loss of hair in some cases.

Choice B reason: This is incorrect because finasteride is not given by injection, but by oral route. The patient should take one tablet daily with or without food.

Choice C reason: This is correct because finasteride can cause birth defects in male fetuses if it is absorbed through the skin or ingested by pregnant women. The patient should wear gloves when handling the tablets and avoid contact with crushed or broken tablets.

Choice D reason: This is incorrect because finasteride can be taken with or without food. However, the patient should take it at the same time each day and follow the provider's instructions.

Choice A reason: This is correct because hemoglobin A1C level reflects the average blood glucose level over the past 2 to 3 months. It is a reliable indicator of the patient's glycemic control and adherence to the antidiabetic therapy. The goal for most patients with type 2 diabetes is to keep the hemoglobin A1C level below 7%.

Choice B reason: This is incorrect because serum insulin level is not a good measure of the patient's adherence to the antidiabetic therapy, as it may vary depending on the type, dose, and timing of the insulin or oral antidiabetic agents. Serum insulin level may also be affected by other factors, such as stress, infection, or exercise.

Choice C reason: This is incorrect because fingerstick fasting blood glucose level only reflects the blood glucose level at a single point in time. It does not provide information about the patient's long-term glycemic control or adherence to the antidiabetic therapy. Fingerstick fasting blood glucose level may also be influenced by the patient's diet, activity, or medication intake before the test.

Choice D reason: This is incorrect because hemoglobin level is not related to the patient's adherence to the antidiabetic therapy, as it measures the amount of oxygen-carrying protein in the red blood cells. Hemoglobin level may be affected by conditions such as anemia, dehydration, or blood loss.