What does the abbreviation "prn" stand for?

The abbreviation "prn" stands for "as needed." This term is commonly used in medical contexts to indicate that a medication or treatment should be administered only when necessary, rather than on a fixed schedule. For example, a physician may prescribe pain medication to be taken "prn," meaning the patient should take it only if they experience pain rather than at regular intervals. This flexibility allows for better management of symptoms according to the patient's individual needs, promoting both effective treatment and patient comfort. The other options do not accurately reflect the meaning of "prn" in medical terminology.