prn

/piː ɑr ɛn/
adverb
  1. As needed or when necessary (used especially in medical contexts).
    • The doctor prescribed the painkiller to be taken prn.
    • She keeps a prn inhaler for her asthma attacks.
    • The nurse noted that the medication should be given prn for anxiety.
What does "prn" mean? | whatsthatwordmean | whatsthatwordmean