Abbreviations
ug
AD, AS, AU
OD, OS, OU
cc
D/C
Intended Meaning
Microgram
Right ear, left ear,
each ear
Right eye, left
eye, each eye
Cubic centimeters
Discharge or
discontinue
Misinterpretation
Mistaken as “mg”
Mistaken as OD, OS, OU (right eye, left eye, each eye)
Mistaken as AD, AD, AU (right ear, left ear, each ear)
Correction
Use “mcg”
Use “right ear”, “left ear”, or
“each ear”
Use “right eye”, “left eye”, or
“each eye”
Use “ml”
Use “discharge” or
“discontinue”
U or u
Unit
Trailing zero after
decimal point (1.0mg)
1 mg
Mistaken as “u” (units)
Premature discontinuation of medications if D/C (intended to mean
“discharge”) has been misinterpreted as “discontinued” when followed
by a list of discharge medications.
Mistaken as bedtime.
Mistaken as IV (intravenous) or 10 (ten)
Mistaken as q.i.d.
Mistaken as “right eye” (OD-oculus dexter), leading to oral liquid
medications administered in the eye.
Mistaken as “q.d.” (daily) or q.i.d. (four times daily) if the “o” is poorly
written
SC mistaken as SL (sublingual); SQ mistaken as “5 every”; the “q” in
“sub q” has been mistaken as “every” (e.g., a heparin dose ordered
“sub q 2 hours before surgery” misunderstood as every 2 hours before
surgery).
Mistaken as the number 0 or 4, causing a 10-fold overdose or greater
(e.g., 4U seen as “40” or 4u seen as “44’); mistaken as “cc” so dose
given in volume instead of units (e.g., 4u seen as 4cc).
Mistaken as 10mg if the decimal point is not seen.
No leading zero before
a decimal dose (e.g., .
5mg)
MgSO4
0.5mg
Mistaken as 5mg if the decimal point is not seen
Magnesium
sulfate
Morphine sulfate
Mistaken as morphine sulfate
Do not use trailing zero for
doses expressed in whole
numbers.
Use zero before a decimal point
when the dose is less than a
whole unit.
Use complete drug name
Mistaken as magnesium sulfate
Use complete drug name
HS
IU
q.d. or QD
o.d. or OD
Half-strength
International unit
Every day
Once daily
q.o.d. or QOD
Every other day
SC, SQ, sub q
Subcutaneous
MS, MSO4
6020 West Parker Road · Plano, Texas 75093
Use “half-strength” or “bedtime”
Use “units”
Use “every day”
Use “daily”
Use “every other day”
Use “subcut” or
“subcutaneously”
Use “unit”