Lessons · Pharmacy · sig abbreviations in plain words
The sig, in plain words
The sig is the directions in shorthand: po is by mouth, bid is twice a day, tid three times, qid four times, q6h every six hours, and prn as needed.
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
What it is for
The sig becomes the sentence on the label that the patient reads at home. Every one of those abbreviations has to come out as plain English, and the count of doses a day that falls out of it is what decides the quantity and the days' supply.
How to think about it
Take the sig one abbreviation at a time and write each in words underneath. Then ask the only number question there is: how many doses does this give in a day? A named frequency you know; an hourly one you divide 24 by.
Worked example
1 tab po bid = one tablet by mouth twice a daypo is by mouth; bid is twice a day.
tid = three times a day, qid = four times a dayTwo, three, four. The three that come up most.
q6h = every 6 hours, so 24 / 6 = 4 doses a dayAn hourly sig is a division, not a memory.
prn = as neededA prn sig has no fixed count a day, which is why a days' supply on one has to be worked from the maximum the order allows.
Your turn
A sig reads q8h. Write how many doses that gives in a day.
24 / 8 = doses a day
Solve one, graded on the server
The trap
Reading bid as every two hours and tid as every three. They are twice a day and three times a day; the hours version is written with a q and a number, and the two shorthands mean very different things.