PRN means 'as needed' and is used for medications such as ...?

• A. Daily insulin at fixed times
• B. Acetaminophen for pain
• C. Antibiotics given on a schedule
• D. Vaccines given annually

Answer: (B)

PRN dosing means giving a medication only when there is a need or symptom present, not at fixed times. This approach suits medicines used to relieve symptoms that come and go, like pain or fever. Acetaminophen given as needed fits well because you administer it when the patient is in pain or has a fever, rather than on a strict schedule, and you monitor to avoid exceeding the safe daily limit. Other options are typically given on a fixed schedule or for preventive purposes (such as insulin at set times, antibiotics on a planned course, or vaccines on a vaccination schedule), so they aren’t used PRN.