What is the medical abbreviation for 'as needed'?

The abbreviation for 'as needed' is PRN, which stands for "pro re nata" in Latin. This term is commonly used in medical contexts to indicate that a medication or treatment should be administered only when required, rather than on a fixed schedule. It allows flexibility in the administration of medications based on the patient's specific needs and circumstances.

In contrast, the other options refer to different medical abbreviations. AD signifies "right ear," AC means "before meals," and QID denotes "four times a day." Understanding these abbreviations is crucial for effective communication in healthcare settings, ensuring that patients receive the appropriate care based on their individual situations.