Failed Communication:

Failed communication covers many of the errors made in the ordering phase, and although ordering is performed by the prescriber, the nurse, the clerk, and the pharmacist who interpret that order are also involved in the communication process.

• Poorly handwritten or verbal orders. Handwriting is a major source of error and has led to inaccurate interpretations of the drug intended, the route of administration, the frequency, and dose. Telephone and verbal orders are likewise prone to misinterpretation. The current use of electronic drug order entry within hospitals and electronic prescribing to pharmacies contributes to increased legibility and consistency of medication orders and prescriptions.
• Drugs with similar-sounding or similar-looking names. Similar sounding names, or names that look similar when handwritten, are frequently confused. Doxorubicin hydrochloride and doxorubicin liposomal, or Lunesta® and Neulasta® are two examples. Mix-ups are more likely when each drug has similar dose ranges and frequencies.

Several of the sound-alike/look-alike drugs were targeted for labeling intervention by the FDA, which requested manufacturers with look-alike names to voluntarily revise the appearance of the established names. The revision visually differentiates the drug names by using "tall man" letters (capitals) to highlight distinguishing syllables (ex.: buPROPrion versus busPIRone or ceFAZolin versus cefTAZidime. See the TALL MAN Lettering table in the Medication Safety Tools section for the list of the pairs of drugs that are commonly confused, often with serious consequences.

• Misuse of zeroes in decimal numbers. Massive, ten-fold overdoses are traceable to not using a leading zero (.2 mg instead of 0.2 mg) or adding an unnecessary trailing zero (2.0 mg instead of 2 mg) in decimal expressions of dose. Similar overdoses are found in decimal expressions in which the decimal point is obscured by poor handwriting, stray marks, or lined orders sheets (e.g., reading 3.1 grams as 31 grams). Underdosing also may occur by the same mechanism and prevent a desired, perhaps life-saving effect.
• Misinterpreted abbreviations. Abbreviations can be misinterpreted or, when used in the dose part of the order, can result in incorrect dose of the correct medication. For example, lower or uppercase "U" for units has been read as a zero, making 10 u of insulin look like 100 units when handwritten. The Latin abbreviation "QOD" for every other day has been misinterpreted as QID (4 times per day). Current widespread use of electronic drug ordering and prescriptions increases legibility; frequency choices are often in plain language such as "every other day" instead of "QOD". See Table 1 for a list of confusing abbreviations and safer alternatives.
• Ambiguous or incomplete orders. Orders that do not clearly specify dose, route, frequency, or indication do not communicate complete information and are open to misinterpretation.

Poor Distribution Practices:

Poor distribution includes error-prone storing practices such as keeping similar-looking products next to each other. Dispensing multidose floor stock vials of potentially dangerous drugs instead of unit (single) dose vials is also associated with error, as is allowing non-pharmacists to dispense medications in the absence of the pharmacist.

Dose Miscalculations:

Dose miscalculations are a prime source of medication error. Also, many medications need to be dose-adjusted for renal or hepatic impairment, age, height and weight, and body composition (i.e., correct for obesity). Complicated dosing formulas provide many opportunities to introduce error. Often vulnerable populations, such as premature infants, children, older adults, and those with serious underlying illnesses, are at greatest risk.

Drug Packaging:

Similar packaging or poorly designed packaging encourages error. Drug companies may use the same design for different formulations, or fail to highlight information about concentration or strength. Lettering, type size, color, and packaging methods can either help or hinder drug identification.

Drug Delivery Systems:

Drug delivery systems include infusion pumps and drip rate controllers. Some models do not prevent free flow of medication, leading to sudden high dose infusion of potent and dangerous medications. The lack of safeguards preventing free flow and programming errors are among the problems encountered with infusion control devices. Newer models, which are integrated with the medication administration record (MAR) via scanned barcodes to match the patient with drug, dose, and timing, contribute to increased dosing safety; however, it is a nursing responsibility to verify the dose and determine that the infusion pump is delivering properly at the point of drug administration.

Incorrect Drug Administration:

Incorrect drug administration covers many problems. Misidentification of a patient, incorrect route of administration, missed doses, or improper drug preparation are types of errors that occur during the administration phase. Barcode scanning to identify the patient and correlate with the correct MAR decreases the likelihood of incorrect drug administration.

Lack of Patient Education:

Safe medication use is enhanced in the hospital and the home when the patient is well informed. The knowledgeable patient can recognize when something has changed in his or her medication regimen and can question the health care professional. At the same time, many issues related to medication errors, such as ambiguous directions, unfamiliarity with a drug, and confusing packaging, affect the patient as well as the health care professional, underscoring the need for careful education. Patient education also enhances adherence, which is a factor in proper medication use.