“Do Not Use” List of Abbreviations

- Source: http://www.jointcommission.org/assets/1/18/dnu_list.pdf

Official “Do Not Use” List¹

Do Not Use	Potential Problem	Use Instead
U, u (unit)	Mistaken for “0” (zero), the number “4” (four) or “cc”	Write "unit"
IU (International Unit)	Mistaken for IV (intravenous) or the number 10 (ten)	Write "International Unit"
Q.D., QD, q.d., qd (daily) Q.O.D., QOD, q.o.d, qod (every other day)	Mistaken for each other Period after the Q mistaken for "I" and the "O" mistaken for "I	Write "daily" Write "every other day"
Trailing zero (X.0 mg)* Lack of leading zero (.X mg)	Decimal point is missed	Write X mg Write 0.X mg
MS MSO4 and MgSO4	Can mean morphine sulfate or magnesium sulfate Confused for one another	Write "morphine sulfate" Write "magnesium sulfate"

¹ Applies to all orders and all medication-related documentation that is handwritten (including free-text computer entry) or on pre-printed forms.

*Exception:  A “trailing zero” may be used only where required to demonstrate the level of precision of the value being reported, such as for laboratory results, imaging studies that report size of lesions, or catheter/tube sizes. It may not be used in medication orders or other medication-related documentation.

Other “Not To Be Used” Abbreviations, Acronyms, and Symbols
Abbreviations	Potential Problem	Preferred Item
μg	Mistaken for mg (milligrams) resulting in one thousandfold dosing overdose.	Write “mcg”
H.S. (for half-strength or Latin abbreviation for bedtime)	Mistaken for either halfstrength or hour of sleep (at bedtime). q.H.S. mistaken for every hour. All can result in a dosing error.	Write out “half-strength” or “at bedtime”
T.I.W. (for three times a week)	Mistaken for three times a day or twice weekly resulting in an overdose.	Write “3 times weekly” or “three times weekly”
S.C. or S.Q. (for subcutaneous)	Mistaken for SL for sublingual, or “5 every”.	Write “Sub-Q”, “subQ”, or subcutaneously
D/C (for discharge)	Interpreted as discontinue whatever medications follow (typically discharge meds).	Write “discharge”
c.c. (for cubic centimeter)	Mistaken for U (units) when poorly written.	Write “ml” for milliliters
A.S., A.D., A.U. (Latin abbreviation for left, right, or both ears) O.S., O.D., O.U. (Latin abbreviation for left, right, or both eyes)	Mistaken for each other (e.g., AS for OS, AD for OD, AU for OU, etc.)	Write “left ear,” “right ear” or “both ears;” “left eye,” “right eye,” or “both eyes”

> and <	Mistakenly used opposite of intended	Use “greater than” or “less than”
/ (slash mark)	Misunderstood as the number 1 (“25 unit/10 units” read as “110" units.	Do not use a slash mark to separate doses. Use “per.”