Medical terminology and sig codes | Order entry and processing

Sig codes are standard prescription abbreviations used commonly in the pharmacy and by healthcare providers. The name “Sig” originates from the Latin word “Signetur,” which means “let it be labeled”. Most Sig codes denote how, how much, when, and how frequently to use a medication. Sig codes can be written in either uppercase or lowercase if the letters are used correctly. Since they are standard codes, they increase the efficiency and speed of processing and filling medications. However, there can be an increased risk of errors due to lack of training or the illegibility of written prescriptions.

Table showing Sig codes denoting how often to take a medication

Sig code	Meaning
prn	As needed
STAT	immediately
2STAT	Take 2 (tablets, capsules, etc.) immediately
q	every
qd	Once a day or every day
qh	Every hourly
q4h	Every four hourly
bid	Twice daily
tid	Three times a day
qid	Four times a day
qod	Every other day
1XD	One time a day
AM	In the morning
PM	In the evening
qAM	Every morning
AMPM	In the morning and evening
hs	At bedtime
ASAP	As soon as possible
c	with
UD	As directed
QS	Quantity sufficient

Table showing Sig codes denoting routes to take a medication

Sig code	Route
ad	In right ear
as	In left ear
au	In both ears
od	In right eye
os	In left eye
ou	In both eyes
po	By mouth
PR	Per rectal
im	intramuscularly
pv	Per vaginally
sl	sublingual
en	In each nostril

Table showing other common abbreviations

Abbreviation	Meaning
gtt(s)	drop(s)
tab	tablet
supp	suppository
SS	One-half
S/S	Swish and swallow
pc	After meals
mg	milligram
ml	milliliter
tbsp	Tablespoon (15 ml)
tsp	Teaspoon (5ml)
cap	capsule
INH	inhale
INJ	inject
SR	Sustained release
XR	Extended-release
NPI	National provider identifier

Examples of how to use the Sig codes and abbreviations

1 tab po daily - take one tablet by mouth daily.
. 1 tsp po TID - take one teaspoon by mouth thrice daily.
1 tbsp po q6h - take one tablespoon orally every six hours.
1-2 gtts qd ad - instill 1-2 drops daily in the right ear.
1 tab pr qd prn - insert one tablet rectally daily as needed.