The abbreviation PRN stands for which of the following?

The abbreviation PRN stands for "as needed." This term is commonly used in medical settings to indicate that a medication or treatment should be administered only when required, rather than on a fixed schedule. For instance, a patient might be prescribed pain medication to take PRN, meaning they should only take it when they are experiencing pain, rather than at regular intervals. This approach allows for more personalized patient care and helps manage symptoms effectively without unnecessary medication use.

Other options refer to specific scheduling instructions for medications but do not align with the meaning of PRN. For instance, "every hour" indicates a strict schedule for medication administration, "before meals" specifies timing related to food intake, and "at bedtime" refers to a specific time of day for taking medication. None of these accurately capture the flexibility that PRN embodies.