Recommendations to Enhance Accuracy of Prescription/Medication Order Writing

Personnel to whom this applies: prescribers; nursing or pharmacy staff (who transcribe verbal prescription orders or rewrite transfer or admission orders when entering or leaving a health care facility); health care administrators/managers.

Technology plays an important role in the delivery of healthcare. Use technology, as appropriate, but evaluate its effectiveness on an ongoing basis. While technology can reduce medication errors and enhance patient safety, it also has the potential to cause new types of unintentional errors. Whenever technology is selected and implemented, it should meet the requirements of this statement.

The Council recommends the following:

  1. All prescription documents are legible. Verbal orders should be minimized. (See the Council's Recommendations to Reduce Medication Errors Associated with Verbal Medication Orders and Prescriptions)
  2. 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.
  3. All prescription orders are 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.
  4. Doses for oral liquids be expressed using only metric weight or volume, e.g mg or mL. If mLs are used it should be associated with a concentration or total dose in milligrams.
  5. Prescribers should include patient-reported age and, when appropriate, weight (metric units is the preferred scale) of the patient on the prescription or medication order. The most common errors in dosage result in pediatric and geriatric populations. For weight-based or body surface area-based drugs, the dose basis should be included. The age (and weight) of a patient can help dispensing health care professionals in their double check of the appropriate drug and dose.
  6. Prescriptions/medication orders include drug name1,  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.
  7. A leading zero always precedes a decimal expression of less than one (use 0.4 mg instead of .4 mg). A terminal or trailing zero should never be used after a decimal (express as 4 mg, not 4.0 mg). 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.
  8. Prescribers avoid the 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. 

    Abbreviation Intended meaning Common Error Correction
    U Units Mistaken as a zero or a four (4) resulting in overdose. Also mistaken for "cc" (cubic centimeters) when poorly written. Use “Unit”
    µg Micrograms Mistaken for "mg" (milligrams) resulting in an overdose. Use “mcg”
    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. Use “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." Use “every other day”
    SC or SQ Subcutaneous Mistaken as "SL" (sublingual) when poorly written. Use “subcut” or “subcutaneously”
    T I W Three times a week Misinterpreted as "three times a day" or "twice a week." Use “3 times weekly”
    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. Use “discharge” and “discontinue”



    Half strength

    At bedtime, hours of sleep

    Misinterpreted as the Latin abbreviation "HS" (hour of sleep).

    Mistaken as half-strength

    Use “half-strength” or “bedtime”
    cc Cubic centimeters Mistaken as "U" (units) when poorly written. Use “mL”
    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) Use “each ear,” “left ear,” or “right ear”
    IU International Unit Mistaken as IV (intravenous) or 10(ten) Use “Units”
    MS, MSO4, MgSO4 Confused for one another Can mean morphine sulfate or magnesium sulfate Use complete drug name


  9. Prescribers avoid vague instructions such as "Take as directed" or "Take/Use as needed" as the sole direction for use. Specific directions to the patient are useful to help reinforce proper medication use, particularly if therapy is to be interrupted for a time. Clear directions are a necessity for the dispenser to: (1) check the proper dose for the patient; and, (2) enable effective patient counseling.
  10. Prescribers should avoid using vague dosing intervals such as “twice daily” or hourly intervals like “every 12 hours”. These instructions can be seen as implicit rather than explicit and harmful to patient understanding. Conversely, using precise dosing times (e.g. 8 AM and 10 PM) may decrease patient adherence due to individual lifestyle patterns, e.g. shiftwork. Write general times of morning, afternoon, and evening to describe dosing intervals.2
  11. Personnel should transcribe verbal prescriptions in designated areas that minimize interruption and distraction.
  12. Practitioners should offer counseling to the patient about their prescriptions. Counseling is often seen as the last attempt in catching errors that occur in prescription writing.3
  13. All persons who prescribe medication have access to adequate and appropriate patient information about the patient at the point of prescribing including medical history, known allergies and their reactions, diagnoses, list of current medications, prescription monitoring program data, and treatment plan to assess the appropriateness of prescribing the medication.
  14. Conduct both initial and ongoing training of prescribers on accepted standards of practice related to prescription writing processes with the ultimate goal of risk identification and medication error prevention.

Actions/Decisions are those of the Council as a whole and may not reflect the views/positions of individual member organizations.


For medications with multiple formulations, be as specific as possible. 

USP NF 37-32 General Chapter <17> Prescription Container Labeling

Cohen MR, Smetzer JL, Westphal JE, Comden SC, Horn DM 2012 Sep-Oct;52(5):584-602. Risk models to improve safety of dispensing high-alert medications in community pharmacies. . J Am Pharm Assoc (2003).