Article Archive
September/October 2014

Preventing Medication Errors
By Mark D. Coggins, PharmD, CGP, FASCP
Today’s Geriatric Medicine
Vol. 7 No. 5 P. 6

The goal of medication therapy is to achieve beneficial therapeutic outcomes and quality of life while minimizing risk to patients. All prescription and nonprescription medications carry the inherent risk of causing adverse drug events that are often unpreventable, even when used at appropriate therapeutic doses and with appropriate monitoring in place.1 Patients are also at risk of medication errors defined as “any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the health care professional, patient, or consumer. Such events may be related to professional practice, health care products, procedures, and systems, including prescribing; order communication; product labeling, packaging, and nomenclature; compounding; dispensing; distribution; administration; education; monitoring; and use,” according to the National Coordinating Council for Medication Error Reporting and prevention.

Medication errors represent a significant concern to the health care system, increasing patient mortality and morbidity as well as increasing health care costs. Even when medication errors result in no patient harm, patient confidence in the health care system can be jeopardized.1

Types of Medication Errors (See Table 1 below)
Medication errors are often classified into different types to assist with medication error reporting and determining the root cause of an error to take steps toward future error prevention. The American Society of Health-System Pharmacists has characterized medication errors in categories including prescribing, omission (ordered drug not administered), timing, use of an unauthorized drug (not authorized by a legitimate prescriber), improper dosing, wrong dosage form, wrong drug preparation, wrong administration technique, deteriorated drug (an expired medication), and monitoring (failure to use laboratory data to monitor toxicity).1

Medication errors are rarely the fault of a single person and are generally multidisciplinary and multifactorial, stemming from the complexity of the medication use process, which includes five core steps: medication prescribing, order processing, dispensing, administration, and monitoring. Evaluating the root cause of medication errors is essential to implementing changes to medication use systems that can prevent the same errors from occurring in the future. The ten key elements of the medication use process should be thoroughly evaluated to determine the root cause of the error.2 They include the following:

• Is patient information accessible and accurate?

• Is drug information accessible, accurate, usable, and up to date?

• Is communication between providers consistent and not complicated?

• Is drug labeling and packaging in place that facilitates safety and the consistent use of appropriate nomenclature?

• Does drug storage and stock facilitate appropriate distribution with standardized drug concentrations and administration times?

• Are drug device acquisition methods that ensure proper use and monitoring in place?

• Does the work environment provide an appropriate workload and limit unfavorable conditions such as poor lighting, noise, and interruptions?

• Is staff competency assessed and can it be improved with opportunities for continuing education?

• Is patient education provided consistently and accurately?

• Are medication use processes in place to evaluate for quality with the ability to redesign to improve safety?

Contributing Factors
Various factors contribute to the potential for medication errors. The top 10 most commonly implicated drugs involved in inpatient drug errors, in descending order, as reported by MEDMARX, a voluntary medication error reporting system introduced in 1998 with more than one million medication error entries, are the following: insulin, albuterol, morphine, potassium chloride, heparin, cefazolin, warfarin, furosemide, levofloxacin, and vancomycin. Contributing factors that related to these inpatient errors included, but were not limited to, “staffing issues, distractions, workload increases, patient issues, shift changes, cross coverage, and fatigue.”3

Patient factors associated with increased risk of medication errors include patients’ advanced age, declining renal and hepatic function, impaired cognition, multiple comorbidities, dependent living, nonadherence to medications, and polypharmacy.3

Inadequate patient information and knowledge of a patient have been implicated as a major cause of prescribing errors. In order to avoid prescribing a drug or selecting a dose that could be inappropriate or harmful to a patient, it is important for the prescriber to have access to the patient’s complete health information record at the time the patient is being seen, with information including patient age and weight, diagnosis history, all medications the patient is taking, lab test results, list of other physicians the patient has seen, past hospitalizations, past dose-response relationships, and drug allergies.1

Patient information should also be readily available to pharmacists and other health care professionals who can provide additional screening for medication dosing errors, drug-drug interactions, allergies, medication for inappropriate indication, and lack of indications. Inclusion of therapeutic goals and the indication for a medication on the prescription or medication order can help minimize errors, especially with high alert medications.1 For example, a number of significant medication errors are described in the literature involving methotrexate, which is often used for people with cancer but also for rheumatoid arthritis, asthma, and inflammatory bowel disease.

Daily dosing of methotrexate is typically used to treat cancer while weekly dosing is used to treat many inflammatory conditions. By including the indication on the order, pharmacists and other health care professionals are better able to identify potential dosing mix-ups where daily dosing has been ordered. Including on the order the indications, such as rheumatoid arthritis, would increase the likelihood that the methotrexate dose would be questioned because of the potential for overdose.

Miscommunication among physicians, pharmacists, and nurses is a common cause of medication errors. The elimination of communication barriers is a key element to medication error reduction strategies.1

In all settings, prescribers and their staff members who may receive messages from pharmacists, nurses, and even patients questioning prescription orders must find ways to make reviewing clarification questions a priority to help increase medication safety. Additionally, pharmacists may find it difficult to clarify prescriber orders with nurses and nurses may find it challenging to monitor medications dispensed by the pharmacy. 

Written Orders
Complete medication orders are critical to helping prevent medication errors and should include the patient’s name, generic drug name, trademarked name (if a specific product is required), route and site of administration, dosage form, dose, strength, quantity, frequency of administration, and the prescriber’s name. The desired therapeutic outcome for each drug should be included.1

Illegibly handwritten prescriptions and orders that are unclear, ambiguous, or overly complex are commonly implicated as causes of medication errors. Prescribers should review all drug orders for accuracy, completeness, and legibility immediately after they have prescribed them. If there is ever a question about legibility of a handwritten prescription, the pharmacist or nurse should always clarify the order with the prescriber.1

Taking the time to ensure the clarity and understandability of prescriptions goes a long way toward eliminating errors. Important steps toward that end include the following1,4:

• Write out instructions rather than using nonstandard or ambiguous abbreviations. For example, write “daily” rather than “q.d.,” which could be misinterpreted as “q.i.d.” resulting in a medication being given four times a day. 

• Avoid vague instructions, such as “take as directed.”

• Specify exact dosage strengths (such as milligrams) rather than dosage form units (such as one tablet or one vial). An exception would be combination drug products, for which the number of dosage form units should be specified.

• Prescribe by standard nomenclature, using the drug’s generic name, official name, or name brand if medically necessary. 

• Spell out the word “units” (eg, 10 units regular insulin) rather than writing “u,” which could be misinterpreted as a zero.

• Use care with zeros and decimal points. The misusage of leading decimals and trailing zeros can be dangerous. The adage “always lead, never follow” can help mitigate errors, which can lead to 10-fold or 100-fold dosage errors (eg, always write 0.1, never write 1.0).

• Provide the reasons or parameters for giving the medication as a pro re nata (PRN or as needed) dose. This is particularly helpful in preventing errors with medications that sound alike and look alike or for medications that are to be given on an as-needed basis (eg, PRN moderate to severe cramping, rather than just PRN).

The Institute for Safe Medication Practices (ISMP) and the FDA have launched a national education campaign to help eliminate one of the most common but preventable sources of medication errors—the use of ambiguous medical abbreviations.

The ISMP and FDA recommend that the ISMP’s List of Error-Prone Abbreviations, Symbols, and Dose Designations, which can be downloaded at, be referenced whenever and wherever medical information is being communicated. This includes internal communications, telephone/verbal prescriptions, computer-generated labels, labels for drug storage bins, medication administration records, and pharmacy and prescriber computer order entry screens, as well as product labeling, industry promotional materials, and medical publications.

Verbal Orders
Verbal medication orders should be discouraged and utilized only when written (or electronic) medication orders are not feasible. Whether in person or by telephone, verbal medication orders should always be read back by the person receiving the order. The prescriber should ask the receiver to repeat the order if it has not already been read back. Additionally, it is important for all health care professionals to be aware of common look-alike and sound-alike medications, and it is helpful to include the indication for the drug in the verbal order. In many cases, spelling the ordered medication name when reading back could further decrease the risk of a medication sound-alike error from occurring.  

To assist health care professionals in preventing medication errors involving sound-alike and look-alike errors with both written and verbally communicated orders, the ISMP has developed a comprehensive list of commonly confused drug names that can be downloaded at

Avoid Interruptions
Interruptions can potentially result in medical errors. It is important for all members of the team to eliminate or minimize interruptions of a nurse who is preparing medications or in the process of dispensing medications. Strategies such as no-distraction zones, “do not disturb” signs over medication preparation areas, and use of colored vests worn by health care providers during the medication administration process, are examples of methods for alerting colleagues not to interrupt health care providers while they are focused on tasks related to the preparation or administration of medications.4

Patient Education
Patients must receive ongoing education from physicians, pharmacists, and the nursing staff about the brand and generic names of medications they are receiving, their indications, usual and actual doses, expected and possible adverse effects, drug or food interactions, and how to protect themselves from errors. Patients can play a vital role in preventing medication errors when they have been encouraged to ask questions and seek answers about their medications before drugs are dispensed at a pharmacy or administered in a hospital. 

Quality Processes and Risk Management
The way to prevent errors is to redesign the systems and processes that lead to errors rather than focusing on correcting the individuals who make errors. Effective strategies for reducing errors include making it difficult for staff to make an error and promoting the detection and correction of errors before they reach a patient and cause harm.

— Mark D. Coggins, PharmD, CGP, FASCP, is senior director of pharmacy services for skilled nursing centers operated by Diversicare in eight states, and is a director on the board of the American Society of Consultant Pharmacists. He was nationally recognized by the Commission for Certification in Geriatric Pharmacy with the 2010 Excellence in Geriatric Pharmacy Practice Award.


Table 1: Types of Medication Errors1



Prescribing Errors

Errors occurring in the prescribing stage of the medication use process.
Examples include incorrect medication selection based on a patient’s diagnosis in the presence of known contraindications or allergies, in the presence of medications with known significant drug-drug interactions without evaluating the risk vs benefit, and inappropriate medication dosing.

A common cause of prescribing errors has been linked to illegible prescriptions and poor communication. 

Omission Errors

Errors occurring when a patient fails to receive an appropriately ordered medication.

Wrong Time Errors

Errors where medications are given outside of the predetermined time frame indicated by health care facilities’ policies. For example, failure to give a medication according to policy, such as all medications should be given within one hour before or after the prescribed administration time.

Unauthorized Drug Error

Errors where a medication is given to a patient without legal authorization from a prescriber.

Dose Errors

Errors where a patient receives dosages of a medication that are either lower or higher than what was ordered by a prescriber. 

Dosage Form Errors

Errors where a patient receives a medication in a dosage form that is different from what was intended by the prescriber. For example, a patient is given medication orally when it was ordered to be given by injection.

Drug Preparation Errors

Drug inappropriately prepared prior to administration. For example, failure to shake a suspension prior to administration or failure to dilute a medication such as potassium liquid with water prior to administration.

Technique Errors

Errors where medications are administered utilizing inappropriate technique or following inappropriate procedures. For example, failure to wait a sufficient amount of time between puffs for inhalers.

Deteriorated Drug Errors

Examples include giving medications that are expired or were inappropriately stored. For example, administering insulin that has been frozen.

Monitoring Errors

Examples include errors occurring as a result of the inappropriate monitoring of therapeutic and/or adverse effects and failure to monitor labs. A high-risk example would be giving warfarin when the patient’s international normalized ratio is found to be significantly elevated, which may result in excessive bleeding.

Compliance Errors

Errors occurring as a result of a patient failing to take medications as prescribed.


Table 2

Commonly Confused Look Alike Sound Alike (LASA) Drugs

Name Brand (generic name)

Confused with Name Brand (generic name)

Celebrex (celecoxib), for arthritis

Celexa (citalopram), for depression

Catapres (clonidine), for hypertension

Klonopin (clonazepam), for anxiety and seizures

Lamisil (terbinafine), for fungal infections

Lamictal (lamotrigine), for seizures and bipolar disorder

Flagyl (metronidazole), an antibiotic

Fortamet, Glucophage (metformin), for type 2 diabetes

Ditropan (oxybutynin), for overactive bladder

Oxycontin (oxycodone), for pain

Prilosec (omeprazole), for ulcers and acid reflux

Prozac (fluoxetine), for depression

Zoloft (sertraline), for depression

Seroquel (quetiapine), for schizophrenia and bipolar disorder

Topamax (topiramate), for seizures

Toprol XL (metoprolol), for hypertension and angina

Zetia (ezetimibe), for cholesterol

Zestril (lisinopril), for hypertension

Zyrtec (cetirizine), for allergies

Zantac (ranitidine), for ulcers and acid reflux


Figure 1

In this example reported by ISMP, the written order for Avandia 8 mg po daily was misread as Coumadin 8 mg po daily. It is possible that an electronic prescription process would have avoided this issue. Additionally, recommendations for the diagnosis to be added to the order (eg, diabetes) could have helped distinguish between an order for Avandia and one for Coumadin.

ISMP’s List of Error-Prone Abbreviations, Symbols, and Dose Designations can be found at


1. ASHP guidelines on preventing medication errors in hospitals. Am J Hosp Pharm. 1993;50(2):305-314.

2. Schafer JJ. A root cause analysis project in a medication safety course. Am J Pharm Educ. 2012;76(6):116.

3. Wittich CM, Burkle CM, Lanier WL. Medication errors: an overview for clinicians. Mayo Clin Proc. 2014;89(8):1116-1125.

4. Improving medication safety. The American Congress of Obstetrics and Gynecologists website. Accessed July 25, 2014.