General
prn
What does prn mean?
Indicates a medication or intervention is to be given only when required rather than on a fixed schedule, such as pain medicine taken only when in pain.
"Morphine 4 milligrams IV PRN for breakthrough pain."
Origin
Abbreviation of Latin 'pro re nata' meaning 'as the thing is needed.'
Frequently asked questions
What does PRN mean on a prescription?
It means the medication is taken as needed rather than on a fixed schedule, for example pain medicine taken only when in pain.
What does PRN stand for?
It comes from the Latin 'pro re nata,' meaning as the thing is needed or as the situation arises.
How is PRN different from scheduled dosing?
Scheduled doses are given at set times regardless of symptoms, while PRN doses are given only when the specified condition, like pain or nausea, is present.
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