Pharmacy Pearl 3 April 2002

**THANKS to Dr Angela Allerman, BCPS for her help with this Pearl **

Inappropriate or undefined medical abbreviations have been problematic for what seems like eternity. Abbreviations may changes from place to place. Poor penmanship has been an issue as well. Electronic provider order entry (POE) has alleviated some of these problems but there are still issues.

If you're trying to propose some recommendations, consider the following suggestions and visit some of the following websites.

1) Avoid abbreviations whenever possible. It's no doubt that everyone is busy and abbreviations save us seconds during our busy days. However, if the receiver of that order is unsure of the abbreviation they may do one of two thing - call you to clarify or, worse yet, guess and proceed. If they have to call for a clarification, that abbreviation really HAS NOT saved you any time. If they proceed with their 'best guess', it may be right and it may be wrong. Are we willing to take that chance? Take the time to write this out clearly.

2) Avoid the abbreviation "U". Instead of "U", write out the word "units". There are reports of patients getting a ten-fold error in insulin dose because a sloppily written "U" was interpreted as an additional zero. For example, 10U of insulin may be interpreted as 100 units.

3) Avoid unnecessary zeros AFTER the decimal point. The reason is the same as in #2. For example, 10.0 could easily be mistaken as 100 - another potential ten-fold dosing error.

4) Do use preceding zeros to bring attention to a decimal point. To illustrate, the decimal point in .5 mg could easily be missed and the dose given may be read as 5mg. Instead, 0.5mg brings attention to the decimal and lessens the chance of a dosing error. Quick case - a 9 month old infant was ordered .5mg of morphine sulfate. The preceding decimal was missed and the infant received 5 mg of morphine sulfate. The baby stopped breathing and arrested.

5) Just because we're using electronic POE in the military side of the house, that does NOT give anyone the license to use the same abbreviations we forbid when handwriting things. MgSO4 could just as easily be mistaken for MSO4 when written in electronic format as handwritten format. What about MTX? Is that methotrexate or mitoxantrone? We need to have a single standard for electronic/print formats as well as handwritten.

See the following chart from www.ismp.org (Institute for Safe Medication Practices), 2 May 2001 issue of "Medication Safety Alert" newsletter

Abbreviation/Dose Expression	Intended Meaning	Misinterpretation	Correction
Apothecary symbols	dram minim	Misunderstood or misread (symbol for dram misread for “3” and minim misread as “mL”).	Use the metric system.
AU	aurio uterque (each ear)	Mistaken for OU (oculo uterque—each eye).	Don’t use this abbreviation.
D/C	discharge discontinue	Premature discontinuation of medications when D/C (intended to mean “discharge”) has been misinterpreted as “discontinued” when followed by a list of drugs.	Use “discharge” and “discontinue.”
Drug names			Use the complete spelling for drug names.
ARAºA	vidarabine	cytarabineARAºC
AZT	zidovudine (RETROVIR)	azathioprine
CPZ	COMPAZINE (prochlorperazine)	chlorpromazine
DPT	DEMEROL-PHENERGAN-THORAZINE	diphtheria-pertussis-tetanus (vaccine)
HCl	hydrochloric acid	potassium chloride (The “H” is misinterpreted as “K.”)
HCT	hydrocortisone	hydrochlorothiazide
HCTZ	hydrochlorothiazide	hydrocortisone (seen as HCT250 mg)
MgSO4	magnesium sulfate	morphine sulfate
MSO4	morphine sulfate	magnesium sulfate
MTX	methotrexate	mitoxantrone
TAC	triamcinolone	tetracaine, ADRENALIN,cocaine
ZnSO4	zinc sulfate	morphine sulfate
Stemmed names
“Nitro” drip	nitroglycerin infusion	sodium nitroprusside infusion
“Norflox”	norfloxacin	NORFLEX
m g	microgram	Mistaken for “mg” when handwritten.	Use “mcg.”
o.d. or OD	once daily	Misinterpreted as “right eye” (OD—oculus dexter)and administration of oral medications in the eye.	Use “daily.”
TIW or tiw	three times a week.	Mistaken as “three times a day.”	Don’t use this abbreviation.
per os	orally	The “os” can be mistaken for “left eye.”	Use “PO,” “by mouth,” or “orally.”
q.d. or QD	every day	Mistaken as q.i.d., especially if the period after the “q” or the tail of the “q” is misunderstood as an “i.”	Use “daily” or “every day.”
qn	nightly or at bedtime	Misinterpreted as “qh” (every hour).	Use “nightly.”
qhs	nightly at bedtime	Misread as every hour.	Use “nightly.”
q6PM, etc.	every evening at 6 PM	Misread as every six hours.	Use 6 PM “nightly.”
q.o.d. or QOD	every other day	Misinterpreted as “q.d.” (daily) or “q.i.d. (four times daily) if the “o” is poorly written.	Use “every other day.”
sub q	subcutaneous	The “q” has been mistaken for “every” (e.g., one heparin dose ordered “sub q 2 hours before surgery” misunderstood as every 2 hours before surgery).	Use “subcut.” or write “subcutaneous.”
SC	subcutaneous	Mistaken for SL (sublingual).	Use “subcut.” or write “subcutaneous.”
U or u	unit	Read as a zero (0) or a four (4), causing a 10‑fold overdose or greater (4U seen as “40” or 4u seen as 44”).	“Unit” has no acceptable abbreviation. Use “unit.”
IU	international unit	Misread as IV (intravenous).	Use “units.”
cc	cubic centimeters	Misread as “U” (units).	Use “mL.”
x3d	for three days	Mistaken for “three doses.”	Use “for three days.”
BT	bedtime	Mistaken as “BID” (twice daily).	Use “hs.”
ss	sliding scale (insulin) or ½ (apothecary)	Mistaken for “55.”	Spell out “sliding scale.” Use “one-half” or use “½.”
> and <	greater than and less than	Mistakenly used opposite of intended.	Use “greater than” or “less than.”
/ (slash mark)	separates two doses or indicates “per”	Misunderstood as the number 1 (“25 unit/10 units” read as “110” units.	Do not use a slash mark to separate doses. Use “per.”
Name letters and dose numbers run together (e.g., Inderal40 mg)	Inderal 40 mg	Misread as Inderal 140 mg.	Always use space between drug name, dose and unit of measure.
Zero after decimal point (1.0)	1 mg	Misread as 10 mg if the decimal point is not seen.	Do not use terminal zeros for doses expressed in whole numbers.
No zero before decimal dose (.5 mg)	0.5 mg	Misread as 5 mg.	Always use zero before a decimal when the dose is less than a whole unit.

Some journal references to peruse and/or use for references:

- Lilley L et al. Look-alike abbreviations: prescriptions for confusion. Am J Nurs 1997;97(11):12

- Davis, N. Approved abbreviation lists. Hosp Pharm. 1996;31:1355

- USP. Council identifies and makes recommendations to improve error-prone aspects of prescription writing. The Standard. 1996; Sept/Oct:3. (Can be found via the www.usp.org webpage)

- ASHP report. ASHP guidelines on preventing medication errors in hospitals. Am J Hosp Pharm. 1993;50:305-14.

An Air Force Surgeon General NOTAM (Notice to Airmen) Jan 2001 states:

"It is estimated that 1 in 131 outpatient and 1 in 854 inpatient deaths are the result of medication errors annually at a cost of $2 billion. We must do all that is possible to reduce medication errors for our patients. The cost in time, money, and human suffering is not only too high, but it is the right thing to do."

Bottom line - with all the recent attention of drugs, the pharmacy benefit (DoD, over 65, Medicare), medications errors, patient safety, the Institute of Medicine (IOM) report, etc. we ALL have to do everything we can to get the right drug to the right patient in the right dose via the right route at the right time. We can't afford to be anything less than 100% accurate in our quest.

This Pearl is meant for academic and educational purposes only. This Pearl is meant to raise important points regarding the safe and cost-effective pharmacotherapy of patients. It is not meant to be the definitive reference for the treatment or prophylaxis of various diseases. Although every effort is taken to ensure this Pearl is correct and factual, errors may occur. The Pharmacoeconomic Center assumes no liability for incorrect information or harm that may occur from the use of the information included in this Pearl.