What does "PRN" mean on a prescription?

The abbreviation "PRN" on a prescription stands for "pro re nata," a Latin phrase that translates to "as needed." This means that the medication should be taken only when required, rather than on a fixed schedule. For example, a patient may be prescribed medication PRN for pain relief and would take it only when experiencing pain, rather than at set times throughout the day. This provides flexibility in managing symptoms effectively without unnecessary doses.

In this context, the other options do not accurately describe the meaning of PRN. "Take with food" refers to specific instructions regarding food intake, "at bedtime" indicates a specific time for administration, and "once daily" specifies a set frequency for taking medication. None of these convey the concept of taking medication as needed, which is the essence of PRN.