Dangerous AbbreviationsThe National Coordinating Council for Medication Error Reporting and Prevention noted these are common prescription writing errors - please keep your eye out for them:
| Abbr. | Intended Meaning |
Common Error |
| U | Units | Mistaken as a zero or a four (4) resulting in overdose. Can also be mistaken for “cc” (cubic centimeters) when written poorly |
| 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 givn “QID” (four times daily) rather than daily |
| Q.O.D. | Latin abbreviation for every other day | Misinterpreted as “QD” (daily) or “QID” (4 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 | Medications have been discontinued prematurely 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) |
Best Practice: Writing scriptsThe National Coordinating Council for Medication Error Reporting and Prevention emphasizes that illegibility of prescriptions and medication orders has resulted in patient injuries or deaths. The Council, therefore, has made the following recommendations to help minimize errors:
• All prescription documents must be legible. Prescribers should move to a direct, computerized, order entry system.
• Prescription orders should include a brief notation of purpose (e.g., for cough), unless considered inappropriate by the prescriber. Notation of purpose can help further assure that the proper medication is dispensed and creates an extra safety check in the process of prescribing and dispensing a medication. The Council does recognize, however, that certain medications and disease states may warrant maintaining confidentiality.
• All prescription orders should be written in the metric system except for therapies that use standard units such as insulin, vitamins, etc. Units should be spelled out rather than writing “U.” The change to the use of the metric system from the archaic apothecary and avoirdupois systems will help avoid misinterpretations of these abbreviations and symbols, and miscalculations when converting to metric, which is used in product labeling and package inserts.
• Prescribers should include age, and when appropriate, weight of the patient on the prescription or medication order. The most common errors in dosage result in pediatric and geriatric populations in which low body weight is common. The age (and weight) of a patient can help dispensing health care professionals in their double check of the appropriate drug and dose.
• The medication order should include drug name, exact metric weight or concentration, and dosage form. Strength should be expressed in metric amounts and concentration should be specified. Each order for a medication should be complete. The pharmacist should check with the prescriber if any information is missing or questionable.
• A leading zero should always precede a decimal expression of less than one. A terminal or trailing zero should never be used after a decimal. Ten-fold errors in drug strength and dosage have occurred with decimals due to the use of a trailing zero or the absence of a leading zero.
• Prescribers should avoid use of abbreviations including those for drug names (e.g., MOM, HCTZ) and Latin directions for use. The abbreviations in the chart below are found to be particularly dangerous because they have been consistently misunderstood and therefore, should never be used. The Council reviewed the uses for many abbreviations and determined that any attempt at standardization of abbreviations would not adequately address the problems of illegibility and misuse.