This is a list of abbreviations used in medical prescriptions (sometimes referred to as sig codes). This listing does not include abbreviations for actual pharmaceuticals (which is a separate article in itself). Capitalization and the use of periods is a matter of style. In the attached list, Latin is not capitalized whereas English acronyms are. The period is used wherever there are letters omitted in the abbreviation. Abbreviations which are officially not to be used as required by the Joint Commission are marked in red. Those abbreviations which are discouraged from use by other organizations are marked in orange.

Key

Official Do-Not-Use list in the United States United States The United States of America is a federal constitutional republic comprising fifty states and a federal district...  required by Joint Commission

Not recommended for use by other organizations

List of abbreviations used in medical prescriptions
Abbreviation	Latin	Meaning	Possible confusion
aa	ana	of each
ad	ad	up to
a.c.	ante cibum	before meals
a.d.	auris dextra	right ear	"a" can be mistaken as an "o" which could read "o.d.", meaning right eye
ad lib.	ad libitum	use as much as one desires; freely
admov.	admove	apply
agit	agita	stir/shake
alt. h.	alternis horis	every other hour
a.m.m.	ad manu medicae	at doctors hand
a.m.	ante meridiem 12-hour clock The 12-hour clock is a time conversion convention in which the 24 hours of the day are divided into two periods called ante meridiem and post meridiem...	morning, before noon
amp		ampule
amt		amount
aq	aqua	water
a.l., a.s.	auris laeva, auris sinistra	left ear	"a" can be mistaken as an "o" which could read "o.s." or "o.l", meaning left eye
A.T.C.		around the clock
a.u.	auris utraque	both ears	"a" can be mistaken as an "o" which could read "o.u.", meaning both eyes
bis	bis	twice
b.d./b.i.d.	bis in die	twice daily
B.M.		bowel movement
BNF		British National Formulary
bol.	bolus Bolus (medicine) In medicine, a bolus is the administration of a medication, drug or other compound that is given to raise its concentration in blood to an effective level...	as a large single dose (usually intravenously)
B.S.		blood sugar
B.S.A		body surface areas
b.t.		bedtime	mistaken for "b.i.d", meaning twice daily
BUCC	bucca	inside cheek
cap., caps.	capsula	capsule
c, c.	cum	with (usually written with a bar on top of the "c")
cib.	cibus	food
cc	cum cibo	with food, (but also cubic centimetre)	mistaken for "U", meaning units; also has an ambiguous meaning; use "mL" or "milliliters"
cf		with food
comp.		compound
cr., crm		cream
CST		Continue same treatment
D5W		dextrose 5% solution (sometimes written as D5W)
D5NS		dextrose 5% in normal saline (0.9%)
D.A.W.		dispense as written (i.e., no generic substitution)
dc, D/C, disc		discontinue or discharge	ambiguous meaning
dieb. alt.	diebus alternis	every other day
dil.		dilute
disp.		dispersible or dispense
div.		divide
d.t.d.	dentur tales doses	give of such doses
D.W.		distilled water
elix.		elixir
e.m.p.	ex modo prescripto	as directed
emuls.	emulsum	emulsion
et	et	and
eod		every other day
ex aq	ex aqua	in water
fl., fld.		fluid
ft.	fiat	make; let it be made
g		gram
gr		grain
gtt(s)	gutta(e)	drop(s)
H		hypodermic
h, hr	hora	hour
h.s.	hora somni	at bedtime
h.s		hour sleep or half-strength	ambiguous meaning
ID		intradermal
IJ, inj	injectio	injection	mistaken for "IV", meaning intravenously
IM		intramuscular Intramuscular injection Intramuscular injection is the injection of a substance directly into a muscle. In medicine, it is one of several alternative methods for the administration of medications . It is used for particular forms of medication that are administered in small amounts...  (with respect to injections)
IN		intranasal	mistaken for "IM", meaning intramuscular, or "IV", meaning intravenously
IP		intraperitoneal
IU		international unit International unit In pharmacology, the International Unit is a unit of measurement for the amount of a substance, based on biological activity or effect. It is abbreviated as IU, as UI , or as IE...	mistaken for "IV" or "10", spell out "international unit"
IV		intravenous Intravenous therapy Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein. The word intravenous simply means "within a vein". Therapies administered intravenously are often called specialty pharmaceuticals...
IVP		intravenous push
IVPB		intravenous piggyback
L.A.S.		label as such
LCD		coal tar solution Coal tar Coal tar is a brown or black liquid of extremely high viscosity, which smells of naphthalene and aromatic hydrocarbons. Coal tar is among the by-products when coal iscarbonized to make coke or gasified to make coal gas...
lin	linimentum	liniment
liq	liquor	solution
lot.		lotion
mane	mane	in the morning
M.	misce	mix
m, min	minimum	a minimum
mcg		microgram Microgram In the metric system, a microgram is a unit of mass equal to one millionth of a gram , or 1/1000 of a milligram. It is one of the smallest units of mass commonly used...
m.d.u.	more dicto utendus	to be used as directed
mEq		milliequivalent
mg		milligram
MgSO4		magnesium sulfate Magnesium sulfate Magnesium sulfate is a chemical compound containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the heptahydrate epsomite , commonly called Epsom salt, from the town of Epsom in Surrey, England, where the salt was distilled from the springs that arise where the...	may be confused with "MSO4", spell out "magnesium sulfate"
mist.	mistura	mix
mitte	mitte	send
mL		millilitre
MS		morphine sulfate or magnesium sulfate Magnesium sulfate Magnesium sulfate is a chemical compound containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the heptahydrate epsomite , commonly called Epsom salt, from the town of Epsom in Surrey, England, where the salt was distilled from the springs that arise where the...	can mean either morphine sulfate or magnesium sulfate, spell out either
MSO4		morphine sulfate	may be confused with "MgSO4", spell out "morphine sulfate"
nebul	nebula	a spray
N.M.T.		not more than
noct.	nocte	at night
non rep.	non repetatur	no repeats
NS		normal saline (0.9%) Saline (medicine) In medicine, saline is a general term referring to a sterile solution of sodium chloride in water but is only sterile when it is to be placed intravenously, otherwise, a saline solution is a salt water solution...
1/2NS		half normal saline (0.45%)
N.T.E.		not to exceed
o_2		both eyes, sometimes written as o2
od	omne in die	every day/once daily (preferred to qd in the UK)
od	oculus dexter	right eye	"o" can be mistaken as an "a" which could read "a.d.", meaning right ear, confusion with omne in die
om	omne mane	every morning
on	omne nocte	every night
o.p.d.		once per day
o.s.	oculus sinister	left eye	"o" can be mistaken as an "a" which could read "a.s.", meaning left ear
o.u.	oculus uterque	both eyes	"o" can be mistaken as an "a" which could read "a.u.", meaning both ears
oz		ounce Ounce The ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 28 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
per	per	by or through
p.c.	post cibum	after meals
pig./pigm.	pigmentum	paint
p.m.	post meridiem 12-hour clock The 12-hour clock is a time conversion convention in which the 24 hours of the day are divided into two periods called ante meridiem and post meridiem...	evening or afternoon
p.o.	per os	by mouth or orally
p.r.	per rectum Rectal (medicine) The rectal route of administration is a way of administering drugs into the rectum to be absorbed by the rectum's blood vesselsThe rectum has numerous amounts of blood vessels available to absorbed the drug introduced into the rectum...	by rectum
PRN, prn	pro re nata Pro re nata Pro re nata is a Latin phrase meaning "in the circumstances" or "as the circumstance arises". It is commonly used in medicine to mean "as needed" or "as the situation arises." It is generally abbreviated to p.r.n. in reference to dosage of prescribed medication that is not scheduled; instead...	as needed
pulv.	pulvis	powder
PV	per vaginam Route of administration A route of administration in pharmacology and toxicology is the path by which a drug, fluid, poison, or other substance is taken into the body.-Classification:Routes of administration are usually classified by application location...	via the vagina
q	quaque	every
q.a.d.	quoque alternis die	every other day
q.a.m.	quaque die ante meridiem	every day before noon
q.d.s.	quater die sumendus	four times a day	can be mistaken for "qd" (every day)
q.p.m.	quaque die post meridiem	every day after noon
q.h.	quaque hora	every hour
q.h.s.	quaque hora somni	every night at bedtime
q.1h, q.1°	quaque 1 hora	every 1 hour; (can replace "1" with other numbers)
q.d., q1d	quaque die	every day	mistaken for "QOD" or "qds", spell out "every day" or "daily"
q.i.d.	quattuor in die	four times a day
q4PM		at 4pm	mistaken to mean every four hours
q.o.d.		every other day	mistaken for "QD", spell out "every other day"
qqh	quater quaque hora	every four hours
q.s.	quantum sufficiat	a sufficient quantity
QWK		every week
R		rectal
rep., rept.	repetatur	repeats
RL, R/L		Ringer's lactate
s	sine	without (usually written with a bar on top of the "s")
s.a.	secundum artum	use your judgement
SC, subc, subcut, subq, SQ		subcutaneous	"SC" can be mistaken for "SL", meaning sublingual; "SQ" can be mistaken for "5Q" meaning five every dose
sig		write on label
SL		sublingually, under the tongue
sol	solutio	solution
s.o.s., si op. sit	si opus sit	if there is a need
ss	semis	one half or sliding scale	ambiguous meaning; mistaken for "55" or "1/2"
SSI, SSRI		sliding scale insulin or sliding scale regular insulin Insulin Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....	mistaken to mean "strong solution Solution In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...  of iodine Iodine Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor.... " or "selective serotonin reuptake inhibitor Selective serotonin reuptake inhibitor Selective serotonin re-uptake inhibitors or serotonin-specific reuptake inhibitor are a class of compounds typically used as antidepressants in the treatment of depression, anxiety disorders, and some personality disorders. The efficacy of SSRIs is disputed... "
stat	statim	immediately
supp	suppositorium	suppository Suppository A suppository is a drug delivery system that is inserted into the rectum , vagina or urethra , where it dissolves.They are used to deliver both systemically-acting and locally-acting medications....
susp		suspension
syr	syrupus	syrup
tab	tabella	tablet
tal., t	talus	such
tbsp		tablespoon Tablespoon A tablespoon is a type of large spoon usually used for serving. A tablespoonful, the capacity of one tablespoon, is commonly used as a measure of volume in cooking...
troche	trochiscus	lozenge
t.d.s.	ter die sumendum	three times a day
t.i.d.	ter in die	three times a day
t.i.w.		three times a week	mistaken for twice a week
top.		topical
T.P.N.		total parenteral nutrition Total parenteral nutrition Parenteral nutrition is feeding a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulae that contain nutrients such as glucose, amino acids, lipids and added vitamins and dietary minerals...
tr, tinc., tinct.		tincture
tsp		teaspoon Teaspoon A teaspoon, an item of cutlery, is a small spoon, commonly part of a silverware place setting, suitable for stirring and sipping the contents of a cup of tea or coffee...
U		unit	mistaken for a "4", "0" or "cc", spell out "unit"
μg		microgram Microgram In the metric system, a microgram is a unit of mass equal to one millionth of a gram , or 1/1000 of a milligram. It is one of the smallest units of mass commonly used...	mistaken for "mg", meaning milligram
u.d., ut. dict.	ut dictum	as directed
ung.	unguentum	ointment
U.S.P.		United States Pharmacopoeia
vag		vaginally
w		with
wf		with food (with meals)
w/o		without
X		times
Y.O.		years old
List of symbols used in prescriptions
Symbols	Latin	Meaning	Possible confusion
@		at	mistaken for "2"; spell out "at"
>		greater than	mistaken for a "7"
<		less than	mistaken for an "L"
℞	take, take this, or take thus	prescription drug Prescription drug A prescription medication is a licensed medicine that is regulated by legislation to require a medical prescription before it can be obtained. The term is used to distinguish it from over-the-counter drugs which can be obtained without a prescription...

Numerical Abbreviation

When expressing a numerical quantity, roman numerals

Roman numerals

The numeral system of ancient Rome, or Roman numerals, uses combinations of letters from the Latin alphabet to signify values. The numbers 1 to 10 can be expressed in Roman numerals as:...

 are commonly used in place of actual digits so as to avoid confusion and foil attempts to receive more medication than prescribed. For numbers 1-3 however, a special abbreviation is used. The number one is written as a capital letter T with one dot overhead. The number two consists of two capital "T" letters connected at the top with a dot over each (resembling the Greek letter pi). The number three is likewise three "T" letters with three dots overhead. A similar system of numbering exists using the lower case letter "i" for the number one.

Discouraged practices

• Abbreviating names of drugs
  DRUGS
  Destroy Rebuild Until God Shows are an American post-hardcore band formed in 2010. They released their debut self-titled album on February 22, 2011.- Formation :...
  
  
• Using apothecary's unit
  Apothecaries' system
  The apothecaries' system of weights is a historical system of mass units that were used by physicians and apothecaries for medical recipes, and also sometimes by scientists. The English version of the system is closely related with the English troy system of weights, the pound and grain being...
  
  s
• Using trailing zero
  Trailing zero
  In mathematics, trailing zeros are a sequence of 0s in the decimal representation of a number, after which no other digits follow....
  
  s or not using a leading zero
  Leading zero
  A leading zero is any 0 digits, that lead a number string in a positional notation. For example, James Bond's famous identifier, 007, has two leading zeros. Leading zeros occupy most significant digits, which could be left blank or omitted for the same numeric value...
  
  

External links

• DAW Codes
• SIG Code Challenge, Interactive Tool for Learning SIG Codes