Home About NCC MERP
About Medication Errors
Council Recommendations
Report a Medication Error
Council Communiqué
Members Page
For Consumers

Upcoming Meetings:

WebEx, July 17, 2014 1PM-4PM

Rockville, October 22, 2014 10AM-4PM

In-person meetings are held
at USP headquarters in
Rockville, MD

NCC MERP 15 Year Anniversary Report

National Coordinating Council for Medication Error Reporting and Prevention

About Medication Errors PrintPrint
Medication Error Definition | Medication Error Category Index | Dangerous Abbreviations | Taxonomy

Dangerous Abbreviations

Abbreviation Intended meaning Common Error
U Units Mistaken as a zero or a four (4) resulting in overdose. Also mistaken for "cc" (cubic centimeters) when poorly written.
µg Micrograms Mistaken for "mg" (milligrams) resulting in an overdose.
Q.D. Latin abbreviation for every day The period after the "Q" has sometimes been mistaken for an " I, " and the drug has been given "QID" (four times daily) rather than daily.
Q.O.D. Latin abbreviation for every other day Misinterpreted as "QD" (daily) or "QID" (four times daily). If the "O" is poorly written, it looks like a period or "I."
SC or SQ Subcutaneous Mistaken as "SL" (sublingual) when poorly written.
T I W Three times a week Misinterpreted as "three times a day" or "twice a week."
D/C Discharge; also discontinue Patient's medications have been prematurely discontinued when D/C, (intended to mean "discharge") was misinterpreted as "discontinue," because it was followed by a list of drugs.
HS Half strength Misinterpreted as the Latin abbreviation "HS" (hour of sleep).
cc Cubic centimeters Mistaken as "U" (units) when poorly written.
AU, AS, AD Latin abbreviation for both ears; left ear; right ear Misinterpreted as the Latin abbreviation "OU" (both eyes); "OS" (left eye); "OD" (right eye)
IU International Unit Mistaken as IV (intravenous) or 10(ten)
MS, MSO4, MgSO4 Confused for one another Can mean morphine sulfate or magnesium sulfate

See the full Council Recommendation, Recommendations to Enhance Accuracy of Prescription Writing.

© 2014 National Coordinating Council for Medication Error Reporting and Prevention. All Rights Reserved. *Permission is hereby granted to reproduce information contained herein provided that such reproduction shall not modify the text and shall include the copyright notice appearing on the pages from which it was copied. This copyright statement will change to the new year after the 1st of every year.