What does q.i.d. denote?

What does q.i.d. denote?

• A. Every hour
• B. Every day
• C. Every 6 hours
• D. Four times a day

Answer: (C)

Q.i.d. comes from the Latin quater in die, meaning four times per day. To achieve four doses in a 24-hour period, the dosing interval is about 6 hours. So the option that says every 6 hours best reflects the regular cadence intended by q.i.d. in practice, since four evenly spaced doses fit into one day. The phrase four times a day is equivalent in frequency, but the interval phrasing here—every 6 hours—directly communicates the spacing. The other options don’t match the idea of four doses per day: hourly would be far more frequent, and daily would be only once.

Q.i.d. comes from the Latin quater in die, meaning four times per day. To achieve four doses in a 24-hour period, the dosing interval is about 6 hours. So the option that says every 6 hours best reflects the regular cadence intended by q.i.d. in practice, since four evenly spaced doses fit into one day. The phrase four times a day is equivalent in frequency, but the interval phrasing here—every 6 hours—directly communicates the spacing. The other options don’t match the idea of four doses per day: hourly would be far more frequent, and daily would be only once.