What does QID stand for in dosing schedules?

• A. Four times per day
• B. Once daily
• C. Three times per day
• D. Once per morning

Answer: (A)

QID means quater in die, a Latin shorthand that indicates four times daily. This is a common prescription abbreviation used to specify how often a medication should be taken within a 24-hour period. It contrasts with other usual terms like BID (twice daily), TID (three times daily), and QD (once daily). So, when you see QID, you should plan for four administrations spread over the day to maintain consistent drug exposure. In practice, the exact timing is chosen to balance effectiveness with convenience and the drug’s pharmacokinetics, which is why QID is the appropriate label for four daily doses.