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Drug Safety and Availability

Feature Article: Medication Errors - Volume 1, Number 4, Summer 2008

Medication errors are "any preventable event that may cause or lead to inappropriate medication use or patient harm, while the medication is in the control of the healthcare professional, patient, or consumer" (see http://www.nccmerp.org/aboutMedErrors.html). These errors may be related to professional practice, the product itself, and/or the procedures and systems related to distribution, dispensing and administration of drugs. For instance, drugs may be given names, shapes, or colors similar to other medications. As illustrated below, similarities in product packaging may result in confusion among healthcare professionals charged with dispensing drugs or among patients taking drugs at home (see Illustration 1).

Illustration 1

hydroxyzine HCL package and hydralazine hydrochloride package
Illustration 1. This illustration is an example of similar looking packaging from the same manufacturer for two unrelated drugs. On the left are 50 mg tablets of hydroxyzine HCL, a sedating antihistamine. On the right are 50 mg tablets of hydralazine HCL, an antihypertensive drug. The packaging of these products may lead to a serious medication error.

Although medication errors can and do occur — FDA has received over 95,000 reports of medication errors since the year 2000 — it is difficult to assess how frequently such errors occur in medical and pharmacy practice. Medication errors such as those involving the wrong drug, an extra or wrong dose, omission of a drug, administering a drug by the wrong route or at an incorrect time are commonly reported to the FDA. Many of these errors can be prevented simply by communicating more effectively. However, some types of errors may require additional interventions such as a change in the product name, labeling and/or packaging to help minimize the likelihood of further confusion. Continued training and vigilance is essential in helping healthcare professionals and FDA reduce the likelihood of an error being made. Reporting medication errors to FDA via MedWatch, or to FDA's partners in this effort, the Institute for Safe Medical Practices (ISMP) and the U.S. Pharmacopeia via their MedMarx program, helps FDA identify factors leading to errors that can be corrected, lessening the likelihood of their recurrence (see http://www.fda.gov/cder/drug/MedErrors/default.htm).

Challenges to Preventing Medication Errors

There are numerous challenges to preventing medication errors. It is common practice, depending on the healthcare setting, to have many individuals involved in the prescribing, dispensing and administration of a medication (e.g., physicians, nurses, pharmacists, and the patient) with the potential for an error to occur at any step in the process. Healthcare professionals should be aware of the sources and types of medication errors so that they may better identify and avoid potential problems before they occur.

There are many steps that healthcare professionals can take to reduce the occurrence of medication errors at the point of prescribing a medication. Two major sources of errors in prescribing are poor penmanship and the use of error-prone abbreviations. For instance, healthcare professionals should be cognizant of their penmanship and use computerized prescriber order entry (CPOE, see below), if available, to lessen any confusion that may result from poorly written prescriptions (see Illustration 2).

There are certain error-prone abbreviations, symbols and dose designations that healthcare professionals should avoid. For example, the abbreviation for microgram, "μg", is often misread for milligram, "mg", when written. FDA and ISMP recommend that the abbreviation "mcg" be used in lieu of "μg". Another common source of misinterpretation and error is the use of the decimal point and a trailing zero. Writing "1.0 mg" can be read as "10 mg" if the decimal point is not clearly visible. Similarly, ".1" mg can be misinterpreted as "1 mg". FDA and ISMP recommend that no trailing zeros be used when denoting doses expressed as whole numbers and that preceding zeros be used whenever a decimal point is needed for a dose that must be administered as a fraction of a whole number. Certain abbreviations can also be misread, for example "HCL", hydrochloride, and "KCL", potassium chloride. FDA and ISMP recommend that the complete drug name be used unless expressed as a salt of the drug. By avoiding the use of abbreviations, symbols and dose designations that are easily confused with each other, the risk of error can be greatly reduced. For a list of error-prone abbreviations, symbols and dose designations, healthcare professionals are referred to http://www.ismp.org/Tools/errorproneabbreviations.pdf .

Illustration 2

handwritten prescription for Metadate
Illustration 2. This illustration is an example of a hand-written prescription for Metadate ER 10 mg tablets. Metadate is a drug used in the treatment of Attention Deficit Hyperactivity Disorder (ADHD). Due to the similarity in name, poor penmanship and the omission of the modifier "ER", the pharmacy filling the prescription incorrectly dispensed methadone 10 mg tablets. Methadone is a morphine-based product used as a heroin substitution therapy and analgesic. Methadone is not used for the treatment of ADHD.

As noted above, another way healthcare professionals can minimize the confusion over handwritten prescriptions (and their misinterpretation; see Illustration 2), and/or potential errors that may result in a drug's misuse, is through the use of technology. For example, CPOE technology is an electronic data entry system that allows healthcare professionals to communicate instructions about a patient at either the point-of-care or remotely. Although not every institution uses CPOE, data have shown that CPOE simplifies and streamlines a patient's care, and significantly reduces medication errors.1 Estimates of the proportion of hospital that have fully implemented CPOE systems range from 37% to 50%.1 CPOE is capable of storing medical histories and can alert healthcare professionals to, among other things, drug allergies, and dangerous drug-drug or drug-device interactions.

A 2008 review of the effects of CPOE on medication errors [MEDLINE (1966 to April 2006) and EMBASE (1976 to April 2006)] indicated that most studies report significant reductions in the relative risk of medication errors when CPOE is used.2 Specifically, 25 of the 27 studies evaluated show a relative risk reduction for medication errors of 13% to 99%. These data strongly support the use of CPOE for the reduction of medication errors.

Another important way to avoid prescribing errors is for healthcare professionals to be up-to-date on the latest information for a product, especially for a drug that may not be commonly used. The professional product label is the best source for information on indications, proper use, and adverse events associated with a drug. The product label is updated as new information becomes available. The label provides important information that healthcare professionals should know prior to prescribing a drug. For instance, a boxed warning, when used, often contains information about serious adverse reactions (e.g., life-threatening) that should be considered when weighing the benefits of prescribing a drug. Special restrictions and distribution programs are also highlighted in boxed warnings.

Starting in 2006, the professional product label has a new look. Included at the top of the label is a highlights section. This feature makes key prescribing information about the drug readily accessible and provides an index to the rest of the information in the label.3 Healthcare professionals should always consult the drug label prior to prescribing a drug they are unfamiliar with or when there has been an update to the prescribing information. The most recent drug labels can be readily accessed on the National Library of Medicine's DailyMed website.

FDA's Role in Reducing Medication Errors

In addition to ensuring that drug labels contain accurate, up-to-date information, FDA also takes an active role identifying factors that may contribute to the incorrect distribution, dispensing, or taking of a medication (see http://www.fda.gov/cder/drug/MedErrors/default.htm). FDA has promulgated regulations (e.g., bar codes) and developed programs aimed at mitigating medication errors. FDA has taken steps to ensure that drug packaging be compatible with emerging technologies (e.g., CPOE). Here are three examples of how FDA is working to reduce medication errors.

Drug names: FDA reviews drug names from both a promotional and safety perspective. The safety review focuses on the avoidance of error. FDA considers whether the proposed name looks and sounds like the names of drug products that are already marketed in the US and evaluates this risk using Failure Mode and Effects Analysis, a process by which potential failures in a system (e.g., drug design) and the effects of such failures (e.g., medication errors) can be assessed. When evaluating the promotional aspects of the name, FDA considers if the proposed name/label is misleading because it overstates the efficacy, minimizes the risk, broadens the indication, makes unsubstantiated superiority claims for the product, or is overly fanciful. The safety goal of this review is to reduce name and label confusion prior to the drug entering the market. Of approximately 400 drug name and labels submitted for approval by pharmaceutical companies each year, FDA rejects one-third for reasons of, but not limited to, appropriateness, similar spelling and pronunciation of the drug name to another currently marketed product, ambiguity in a drug name and/or identifier, or being misleading.

Over-the-counter (OTC) Drug Labeling: For OTC drugs, consumers must rely on the information on the package in order to safely and properly use these medications, or to give them to children or others they are caring for. The OTC label is the primary mechanism by which all necessary safety and effectiveness information associated with the use of the OTC drug is conveyed to the consumer. In 1999, FDA redesigned and standardized the components of the OTC label so that information about the drug is readily available and can be easily read by the consumer. The label describes the purpose of the compound and any safety information and warnings associated with the drug. The label also clearly outlines how to use the drug appropriately. In addition, standardization of the OTC label reduces confusion among OTC drugs as a class.

Bar Codes: In 2004, FDA published a final rule requiring a bar code be placed on all drugs distributed and used in hospital settings. According to the rule, manufacturers, repackers, relabelers and private label distributors of drug products commonly used in hospitals must place a bar code on their product. The function of the bar code is to reduce error by increasing standardization among products so that, in conjunction with bar code scanning technology, the right patient can get the right drug at the right time. Supporting the use of bar codes are reports indicating that bar codes reduce dispensing errors and adverse drug events by 96% and 97%, respectively.4 In 2006, the American Society of Health-System Pharmacists (ASHP) reported that 13.2% of hospitals have adopted technology that utilizes bar code technology. This rate constitutes a 3.8% increase in bar code utilization from the previous year.5 The bar code rule highlights FDA's commitment to patient safety by integrating new labeling components that works with new technology.

By increasing awareness about medication errors, and instituting rules that standardize the use and promotion of medications, FDA seeks to reduce the incidence of medication errors and the impact these errors have on patients, families and the healthcare system. FDA closely monitors medication error reports as they are received, and issues warnings and/or intercedes when necessary. Healthcare providers are encouraged to continue to report medication errors to MedWatch or through FDA's partner organizations such as the ISMP.

Relevant Websites

FDA's medication error website

FDA 101: Medication Errors

Institute for Safe Medical Practices

U.S. Pharmacopeia MedMarx Program


  1. Ammenwerth E, Schnell-Inderst P, Machan C, Siebert U. The Effect of Electronic Prescribing on Medication Errors and Adverse Drug Events: A Systematic Review. J Am Med Inform Assoc. 2008 Jun 25. [Epub ahead of print]
  2. Ford EW, McAlearney AS, Phillips MT, et al. Predicting computerized physician order entry system adoption in US hospitals: can the federal mandate be met? Int J Med Inform. 2008;77(8):539-45.
  3. Requirements on Content and Format of Labeling for Human Prescription drug and biological Products and Draft Guidances and Two Guidances for Industry on the Content and Format of Labeling for Human Prescription Drug and Biological Products: Final Rule and Notices . Federal Register. January 24, 2006; 71(15):3922-3997.
  4. Poon EG, Cina JL, Churchill W, et al. Medication dispensing errors and potential adverse drug events before and after implementing bar code technology in the pharmacy. Ann Intern Med. 2006; 145(6):426-34.
  5. Pedersen CA, Schneider PJ, Scheckelhoff DJ. ASHP national survey of pharmacy practice in hospital settings: dispensing and administration--2005. Am J Health Syst Pharm. 2006; 63(4):327-45.