What Does "PRN" Mean on a Prescription?


Quick Answer

On a prescription, the notation "prn" indicates that a medication is to be taken as needed instead of on a regular dosing schedule. The abbreviation is derived from the Latin "pro re nata," which translates to "as the thing is needed," according to the American Society of Health-System Pharmacists.

Continue Reading
Related Videos

Full Answer

Medications only needed for a specific situation are sometimes only taken "prn." For example, medications that treat pain, constipation, allergy flares and even some types of chest pain are sometimes prescribed without a regular dosing schedule. When these medicines are prescribed, the prescribing doctor or pharmacist filing the prescription usually counsels the patient on when to take it, according to ASHP.

Learn more about Medications & Vitamins

Related Questions