Final answer:
The nurse must clarify the dosage, route, and drug name in the medication order, where 'APAP' stands for acetaminophen, to ensure proper pain management and avoid potential toxicity.
Step-by-step explanation:
The nurse should clarify the following parts of the medication order: the dosage, the route, and the drug name. The abbreviation 'APAP' refers to acetaminophen, a non-opioid pain reliever. However, clarifying the exact dosage is critical to avoid toxicity and ensure effective pain management, especially since dosing can vary among individuals. Moreover, the administration route should be confirmed to ensure proper delivery of the medication. Other details like the mechanism of action and the frequency ('every six hours as needed') are usually standard for acetaminophen, and the indication ('for pain') is already clear from the order.