A nurse is caring for a client who is taking azathioprine to treat rheumatoid arthritis. Which of the following laboratory values indicates an adverse effect of this medication?

Choice A Reason:
Increase in serum glucose is incorrect. Desmopressin, which is a synthetic form of vasopressin, primarily affects water reabsorption in the kidneys and doesn't directly impact glucose levels. Therefore, an increase in serum glucose wouldn't be an expected therapeutic response to desmopressin for diabetes insipidus.
Choice B Reason:
Decrease in blood pressure is incorrect. Desmopressin is primarily used for its antidiuretic effect, concentrating urine by increasing water reabsorption in the kidneys. It typically doesn't have a significant impact on blood pressure. Therefore, a decrease in blood pressure wouldn't typically be an anticipated therapeutic response to desmopressin in this context.
Choice C Reason:
Decrease in urine output is correct. Desmopressin is a synthetic form of vasopressin (antidiuretic hormone) used to treat diabetes insipidus, a condition characterized by excessive urination and extreme thirst due to the inability to concentrate urine. The primary goal of desmopressin is to reduce urine output by increasing water reabsorption in the kidneys, thereby decreasing excessive urination. Therefore, a decrease in urine output would indicate a therapeutic response to the medication in this context.
Choice D Reason:
Increase in WBC count is incorrect. Desmopressin's action is centered on affecting kidney function by regulating water reabsorption and does not involve changes in white blood cell count. Consequently, an increase in WBC count wouldn't be an expected therapeutic response to desmopressin for diabetes insipidus.

Choice A Reason:
INR (International Normalized Ratio) is incorrect. INR is a measurement used to monitor the effects of anticoagulants like warfarin. It assesses the blood's ability to clot. Filgrastim does not directly affect INR levels, so monitoring INR would not provide information about the effectiveness of filgrastim in stimulating white blood cell production.
Choice B Reason:
BUN (Blood Urea Nitrogen) is incorrect. BUN levels primarily indicate kidney function and hydration status. They are not directly influenced by filgrastim treatment. Monitoring BUN is essential for assessing kidney function but does not reflect the effectiveness of filgrastim therapy in increasing white blood cell counts.
Choice C Reason:
WBC count is correct. Filgrastim is a medication that stimulates the production of white blood cells (WBCs), particularly neutrophils. Therefore, the key laboratory value to monitor for assessing the effectiveness of filgrastim therapy is the WBC count. An increase in the WBC count, particularly in the neutrophil count, signifies the intended therapeutic effect of filgrastim in boosting the immune system's response by increasing the production of these infection-fighting cells.
Choice D Reason:
Potassium level is incorrect. Potassium levels are crucial for heart and muscle function. While certain medications might affect potassium levels, filgrastim's primary action is on stimulating white blood cell production and does not directly impact potassium levels. Monitoring potassium levels is essential for overall health but does not specifically indicate the effectiveness of filgrastim treatment.