Correct Answer: C

Rationale: Oprelvekin is a medication that stimulates platelet production. Therefore, monitoring the platelet count is essential to assess the effectiveness of this drug. The expected outcome for oprelvekin therapy is a platelet count greater than 50,000/mm^3. Changes in platelet count can indicate the response to the medication and help in adjusting the treatment plan accordingly.

Correct Answer: A

Rationale: Nausea is a potential sign of Digoxin toxicity. Other signs include vomiting, visual disturbances, and confusion. These symptoms should be closely monitored by the nurse to detect toxicity early.

Correct Answer: B

Rationale: The correct answer is to take Ferrous sulfate on an empty stomach. This medication is best absorbed when taken 1 hour before or 2 hours after meals. Instructing the client to take it with milk, before bedtime, or with antacids can decrease its absorption and effectiveness.

Correct Answer: D

Rationale: Butorphanol is an opioid agonist/antagonist that can precipitate withdrawal symptoms in opioid-dependent individuals. Symptoms of abstinence syndrome can include abdominal pain, fever, and anxiety. This occurs because butorphanol competes with and displaces opioid agonists from receptors, leading to withdrawal symptoms in opioid-dependent clients.

Correct Answer: A

Rationale: The correct answer is to instruct the client to avoid salt substitutes. Lisinopril, an ACE inhibitor, can lead to hyperkalemia, so it is essential to avoid salt substitutes containing potassium, which can further increase potassium levels in the body. This instruction aims to prevent potential adverse effects and ensure the client's safety while taking Lisinopril.