3.3 Medical Abbreviations, Acronyms, and Symbols

The origin of medical terminology can be traced back to medical treatments developed by the Greek physicians Hippocrates and Galen, as well as ancient practitioners of the Roman Empire. Their discoveries shaped medical science and, as a result, approximately 75% of medical terminology is rooted in the Greek and Latin languages. Medical terminology uses approximately 35,000 abbreviations, acronyms, and symbols as a shorthand method in healthcare communications. It is important for you to become familiar with this specialized healthcare language that is used on prescriptions, medication orders, and medication labels.

Learning Healthcare Abbreviations and Acronyms

Healthcare abbreviations often use the initial letters of words or phrases as shorthand on prescriptions and medication orders. Many of these abbreviations are derived from the initial letters of Latin words or phrases and refer to common routes of administration, times of administration, or dosage forms. For example, the abbreviation po is from the Latin words per os, meaning “by mouth” (route of administration); the abbreviation prn comes from the Latin words pro re nata, meaning “as necessary” (time of administration); and the abbreviation ung is from the Latin word unguentum, meaning “salve” or “ointment” (dosage form).

Like abbreviations, acronyms are often formed from the initial letters of terms or phrases. However, these letters are frequently capitalized and are pronounced together as one term, not as separate letters. For example, the acronym AIDS is a shortened form of “acquired immune deficiency syndrome” and is pronounced as the word “aids.” The acronym SUBCUT (also expressed as subcut) is an abbreviated form of “subcutaneous” and is pronounced “sub-cute.” The acronym NICU is an abbreviated form of “neonatal intensive care unit” and is pronounced “nick-u.”

When abbreviations and acronyms are standardized (have only one meaning) and are clearly written, this medical shorthand saves prescribers and other healthcare practitioners space and time. However, the use of this shorthand can cause serious problems if the medical abbreviations are misinterpreted by others. Sometimes, confusion occurs when the same set of letters has two different meanings. For example, the use of the abbreviation IVP on a hospital medication order may mean two different procedures. This abbreviation may mean “IV Push,” or the use of a syringe to inject an IV medication into a vein. However, the abbreviation IVP may also indicate a request for an “intravenous pyelogram,” or an X-ray examination of the urinary tract.

Abbreviations are also problematic when they are not expressed clearly. For example, the abbreviation qhs means “nightly at bedtime” but could be misread as qhr, meaning “every hour.” Consider a situation where a dose was meant to be ordered as 10 units. If the order was written using U as an abbreviation for “units,” an error could occur. The U could be misread for a 0 (zero), and the patient could receive 100 units instead of the intended 10 (a tenfold overdose).

Certain abbreviations are so error-prone that The Joint Commission (TJC)—an independent organization that evaluates and accredits practices in hospital systems—has declared that these abbreviations are absolutely unacceptable for use in accredited institutions. To that end, TJC has published the Official “Do Not Use” List containing abbreviations that may lead to confusion among healthcare personnel and, consequently, may result in medication errors. This list can be found at http://PhCalc7e.ParadigmEducation.com/JointCommission.

Another organization, the Institute for Safe Medication Practices (ISMP), has published an extensive list of dangerous abbreviations and symbols to avoid in the healthcare setting. This document, called the ISMP’s List of Error-Prone Abbreviations, Symbols, and Dose Designations, can be found at http://PhCalc7e.ParadigmEducation.com/ISMP.

You should commit the common abbreviations to memory because they are a part of the pharmacy technician’s everyday language. You may want to start by memorizing the abbreviations that indicate how many times per day a patient should take a medication: BID (twice daily), TID (three times daily), and QID (four times daily). The abbreviations are sometimes written in lowercase letters and sometimes written in uppercase letters. The use of periods should be avoided as these punctuation marks can be a source of medication errors. The letter q means “every” and is sometimes placed in front of other abbreviations. Common prescription and medication order abbreviations are listed in Table 3.3. For an expanded list, refer to Appendix B: Common Pharmacy Abbreviations and Acronyms in this textbook.

Recognizing Common Medical Symbols

In addition to knowing medical abbreviations and acronyms commonly seen in pharmacy practice, you must also recognize a number of symbols used on medication orders in particular. Symbols such as ↑ and ↓ are frequently used by prescribers to indicate “increase” and “decrease,” respectively. For example, a physician may order a change in an IV flow rate to increase the dose of a medication, such as ↑ normal saline to 150 mL per hour. Another common symbol is the Greek delta symbol (∆), which is used to indicate a desired change. For example, the medication order famotidine ∆ from 20 mg IV to 40 mg PO communicates that the prescriber wants to change the dose (from 20 mg to 40 mg) and the route of administration (from intravenous [IV] to oral [PO]).

Because symbols are drawn by hand, and handwriting may be poor or at least vary significantly among personnel, symbols can be misinterpreted easily. Therefore, you should take extra care when using or interpreting medical symbols. Computer-generated symbols are preferred over handwritten symbols, whenever possible.

Translating Directions for Patients

Because most patients are not familiar with the abbreviations and acronyms used on prescriptions, directions must be “translated” from the “sig” and written on the medication label placed on the dispensing package or container so that patients can understand the directions. Sometimes, descriptive terms are added, if appropriate. For example, a prescription for a fentanyl transdermal patch may have the sig q 3d. The pharmacy label on the patient’s package, however, must state, “Apply one patch every 72 hours.” Similarly, a prescription for hydrochlorothiazide 25 mg tablets may bear a sig of 12.5 mg po qam, but the pharmacy label on the patient’s container must state, “Take one-half (½) tablet by mouth every morning.”

It is important that directions for taking a medication be stated in clear terms on the medication label affixed to the dispensing package or container, even if the patient’s physician and pharmacist provide verbal instructions to the patient. Written directions on a label provide a necessary reminder to a patient at every dose, which helps to ensure safe medication use.

Even with appropriate translation of prescription instructions, patients may still require additional assistance. For example, patients who are receiving liquid medications typically have their prescribed doses designated in milliliters. Most patients are not familiar with measuring volumes in milliliters. Therefore, special measuring devices—such as dosing syringes, spoons, and cups—are typically dispensed with the medications.

3.3 Problem Set

Write out the meanings of these common abbreviations used in prescriptions and medication orders.

1. bid

2. DAW

3. IM

4. IV

5. mL

6. NKA

7. npo

8. q3h

9. qid

10. tid

Applications

Translate the following directions from a prescription order into wording that would be appropriate on a label for the patient’s use.

11.  

    

    Diphenhydramine 25 mg Capsules

    cap po four times daily prn itching

    

     

     

12.  

    

    Nitroglycerin Transdermal Patch

    on qhs off qam

13.  

    Nitroglycerin 2% Ointment

    

    Apply ½ inch (7.5 mg) BID; qam and 6h after first application.

14.  

    

    Nateglinide 60 mg Tablets

    120 mg po tid ac

15.  

    

    Potassium Chloride 20 mEq Tablets

    10 mEq po bid

Self-check your work in Appendix A.