Correct Answer: D

Rationale: The primary action of tamoxifen, an antineoplastic medication used in metastatic breast carcinoma, is to compete with estradiol for binding to estrogen receptors in tissues with high receptor concentrations. By doing so, tamoxifen reduces DNA synthesis and estrogen response, leading to its therapeutic effect in inhibiting the growth of estrogen-sensitive breast cancer cells.

Correct Answer: A

Rationale: When ciprofloxacin (Cipro) is given with warfarin sodium (Coumadin), it can potentiate the effects of warfarin, leading to an increased risk of bleeding. Therefore, the nurse should closely monitor the client's INR levels and watch for signs of bleeding such as bruising, petechiae, or black tarry stools.

Correct Answer: D

Rationale: The correct answer is D because taking metoprolol (Lopressor) at bedtime is not specifically recommended. Metoprolol should be taken with food to enhance absorption. It is crucial for the client not to stop taking the medication abruptly to prevent rebound hypertension or other adverse effects. Additionally, monitoring the pulse before taking metoprolol is important for assessing its effect on heart rate.

Correct Answer: A

Rationale: Allopurinol is an antigout medication that works by reducing the production of uric acid in the body. To prevent kidney stones and promote the excretion of uric acid, increased fluid intake is essential. Instructing the client to drink 3000 mL of fluid per day helps to reduce the risk of kidney stones and assists in the elimination of uric acid, thereby enhancing the effectiveness of allopurinol therapy.

Correct Answer: B

Rationale: Azathioprine is an immunosuppressant taken for life. Discontinuing the medication after 14 days is incorrect.