QID

Medical abbreviation · Prescription

QID
Stands forQuater in die (four times a day)
CategoriesMedical

QID stands for Quater in die (four times a day), a prescription abbreviation.

Frequency calling for four doses spread through the day, often with meals and at bedtime for oral drugs. Unlike q6h, a QID schedule usually does not require waking the patient overnight.

Example: Nystatin suspension 5 mL swish and swallow QID for oral thrush.

Usage notes

Latin "quater in die". Also written q.i.d. or qid; the UK form is "qds" (quater die sumendum). QID is one reason QD was banned: a poorly written "QD" or "Q.D." has been misread as QID, quadrupling a daily dose. Writing "4 times daily" removes any ambiguity.

More prescription abbreviations

  • q8h – Every 8 hours
  • qAM – Every morning
  • QD – Quaque die (every day, once daily)
  • qds – Quater die sumendum (to be taken four times a day)
  • qh – Quaque hora (every hour)
  • QHS – Quaque hora somni (every night at bedtime)
  • qn – Quaque nocte (every night)
  • QOD – Quaque altera die (every other day)
  • qPM – Every evening
  • qty – Quantity
  • qwk – Every week (once weekly)
  • Rf – Refills

See all 77 prescription abbreviations →

This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.