What does "prn" mean on a prescription?

The term "prn" is derived from the Latin phrase "pro re nata," which translates to "as needed." When a prescription includes "prn," it indicates that the medication should be taken only when required, rather than at scheduled intervals. This allows for flexibility in dosing based on the patient's current symptoms or conditions. For example, a physician might prescribe a pain reliever with "prn" instructions, indicating that the patient should take it only when they experience pain, rather than adhering to a strict dosing schedule.

The other options reflect different instructions that do not align with the meaning of "prn." "Take with food" refers to the timing and conditions for taking medication to enhance absorption or reduce gastrointestinal upset. "Every day" indicates a fixed daily schedule for medication intake and does not allow for variable dosing based on symptoms. "As prescribed" is a general term that could apply to any medication instructions but lacks the specificity of "as needed." Therefore, the correct interpretation of "prn" in a prescription context is indeed "as needed."