Cases & Commentaries

Bad Writing, Wrong Medication

Spotlight Case
Commentary By Beth Devine, PharmD, MBA, PhD

Case Objectives

  • Differentiate between a medication error
    and an adverse drug event.
  • Appreciate the system complexities
    involved in medication errors that occur in ambulatory
  • List at least three to five elements
    that comprise a framework for conducting a root cause analysis of a
    medication error.

Case & Commentary: Part 1

A 73-year-old man with a long-standing cardiac
arrhythmia came to the ambulatory clinic for a routine follow-up
visit. After evaluation, he received a handwritten prescription for
Rythmol (propafenone), 150 mg, which had been his usual
antiarrhythmic medication for the past 3 years. The patient
delivered the prescription to the clinic pharmacy, and it was
filled. Shortly after starting to take the medication, the man
began to feel "very, very bad," with nausea, sweating, and an
irregular heartbeat. These symptoms persisted for 2 weeks, and the
patient called his physician to schedule another appointment. The
patient brought the medication to his physician, stating that the
Rythmol tablets looked different from their usual

Both medication errors and adverse drug events
(ADEs) are types of medication safety events. To provide a
framework for discussion, it is useful to begin with a definition
of each. The National Coordinating Council on Medication Error
Reporting and Prevention defines a medication error 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
Such events may be related to any aspect of medication use. An
ADE is defined as "an injury resulting from a medical
intervention related to a drug."(2) The
relationship between the two is illustrated in the Figure. Medication errors that cause harm become
preventable ADEs; errors that do not cause harm are termed
potential ADEs. Some ADEs are not due to errors and are
not preventable.

Research that characterizes the epidemiology of
medication errors and ADEs in the ambulatory setting is sparse,
both due to the fragmented nature of most outpatient care and the
limitations of the relevant data sources. Nonetheless, it is
estimated that 21% of handwritten prescriptions contain at least
one prescription-writing error.(3)
Most research has focused on dispensing errors, and investigators
estimate that between 1.7% and 24% of prescriptions are dispensed
erroneously, and that 1.5% to 4% of these errors could cause
Labeling errors and wrong-drug errors occur frequently.(4,5)
Investigators estimate that between 11% and 38% of ADEs in the
ambulatory setting are preventable (6-9),
and one study found that preventable ADEs were more likely than
nonpreventable ADEs to be serious, life-threatening, or fatal (54%
versus 30%, respectively).(9)
They further estimated the direct cost of a preventable ADE to be
$1983 in older adults, and the estimated annual direct cost of
preventable ADEs to the entire Medicare population to be $887
million (both 2000 $). These costs were attributed to inpatient
stays (62%), emergency department visits (6%), outpatient care
(28%), and medications (4%). These estimates do not include costs
to the patient, productivity losses, or decrements in quality of

Data from the 2006 National Ambulatory Medical
Care Survey indicate that one or more drugs were provided or
prescribed in 636.7 million of the 902 million office visits made
to physicians in 2006.(10)
With such high prescription volumes, adopting strategies to
optimize medication safety in the ambulatory setting is a crucial
component of improving the quality and safety of patient care.

In this case, the patient's
statement that the physical characteristics of the dispensed
medication differed from those of his usual prescription, coupled
with the temporal association between prescription filling and his
symptoms of nausea, sweating and irregular heartbeat, send a clear
signal that a dispensing error likely occurred.

Case & Commentary: Part 2

Based upon the altered appearance of the
tablets, both the patient and the physician suspected that this
might not be the correct drug. Upon investigation, the physician
identified the patient's medication as Synthroid (levothyroxine),
150 mcg, not the intended Rythmol (propafenone), 150 mg. When the
physician spoke with the pharmacist who had filled the
prescription, it became apparent that a medication dispensing error
had occurred due to unclear handwriting on the original
prescription. The patient's symptoms of nausea, sweating, and
irregular heartbeat were related to both inadvertent, abrupt
discontinuation of Rythmol and the unnecessary use of Synthroid at
a relatively high initial dosage. Synthroid was immediately
discontinued, and the patient restarted Rythmol as originally

In a systems-based approach to medical
error prevention, we recognize that many errors stem from
weaknesses in individual components of the health care system, that
these weaknesses are best improved through multidisciplinary
efforts, and that determining who was involved is less important
than identifying and addressing the root causes of the
The Institute for Safe Medication Practices (ISMP) actively
promotes this approach and has conducted hundreds of root cause analyses (RCAs) after error occurrences. In
all cases, the causes have been multifactorial and have involved
many processes, more than one line of responsibility, and
organization-wide systems.(11)
ISMP has identified ten key system elements that influence
medication safety: (i) access to patient-specific information; (ii)
access to drug information; (iii) adequate communication; (iv)
proper labeling, packaging, and nomenclature; (v) drug
standardization, storage, and monitoring; (vi) medication delivery
device use and monitoring; (vii) sufficient environmental support;
(viii) staff competency and education; (ix) patient education; and
(x) quality improvement and risk management programs.

Much is made of the roles of electronic
medication records (EMRs), computerized provider order entry (CPOE)
systems, and bar-coding technologies in reducing errors. The
Institute of Medicine strongly supports greater use of information
technology to improve medication safety.(12) CPOE systems, when correctly implemented, are
associated with a reduction in errors—in some studies by more
than 50%.(13,14)
In a recent study that investigated the impact of a CPOE system on
errors in the ambulatory clinic setting, the greatest reduction was
seen in the odds of an error of illegibility (97% reduction),
followed by use of inappropriate abbreviations (94%), and missing
information (85%).(14)
The literature is silent on the impact of bar-coding in reducing
medication errors in the community pharmacy setting.

Recent survey data from the National Center for
Health Statistics indicate that approximately 17% of office-based
physicians used a "basic" EMR in 2008 and 4% used a "fully
functional" system.(15) As
defined, a basic system included functionality for prescription
ordering, while a fully functional system also allowed for
electronic prescription transmittal. When prescriptions are
electronically prescribed, they cannot always be transmitted
directly to the pharmacy dispensing computer system, but may
require that the prescription be sent via facsimile. Pharmacies can
rescan these into the pharmacy system for documentation purposes,
but they must still re-enter the prescription data into the
pharmacy computer system to dispense the medication(s). Even when
direct transmittal is successful, routed and delivered through an
interchange used by the pharmacy benefit manager, the prescription
often requires modification to ready it for dispensing. Finally,
community pharmacy computer systems are seldom linked to EMRs and
CPOE systems. At a minimum, pharmacy dispensing computer systems do
contain a record of patient demographic information, allergies, and
a list of prescriptions filled at that pharmacy. They provide alert
checking for allergies, duplicate medications, and drug–drug
interactions. Virtually all pharmacies have access to drug
information with online information being more up-to-date than
paper versions.

Pharmacists are accustomed to correctly
interpreting handwritten prescriptions. When illegibility raises
doubt in a pharmacist's mind, the pharmacist may seek clarification
by viewing the EMR, checking with the patient, or telephoning the
prescriber's office. Once clarified, bar-coding can be used to
match each unique prescription to the drug product. Once a
prescription is filled, the purchase transaction is often handled
by a pharmacy assistant or technician. The Omnibus Budget
Reconciliation Act of 1990 required states to establish standards
governing patient counseling for prescriptions.(16) Most states require the offer of counseling,
which is usually made by this same technician. If a patient
accepts, face-to-face counseling by a pharmacist is required; in
64% of states for new prescriptions only, in the remainder for both
new prescriptions and refills. This interchange provides the
opportunity for a final check to prevent medication errors. Yet
patients often refuse counseling, especially for medication
refills. In one recent study, 43 of 100 trained shoppers received
verbal counseling for a new prescription. In 16 of the cases, the
shopper prompted counseling. All shoppers received written
information covering an average of 90% of required
topics.(17) In
a similar study, 63% of trained shoppers received verbal
Characteristics associated with more frequent counseling were
younger pharmacists, increased intensity of state counseling
requirements, and less busy pharmacies.

Historically, the medication
error described in this case might have been dismissed solely as a
dispensing error caused by an illegible prescription. Conducting an
RCA, using ISMP's ten key system elements as a framework, can shed
light on the underlying causes of the error, and on improvements
that could be made to mitigate chances of recurrence.(19)
First, the pharmacist may have lacked adequate patient-specific
information with which to confirm the correct medication. It
appears that the intended purpose was not written on the
prescription. The ISMP advocates that the intended use be indicated
on each prescription as an aid for pharmacists and for
patients.(11) A
CPOE system was not used to prescribe or to transmit the
prescription. The pharmacy was associated with the clinic, but we
do not know whether the clinic had an EMR in place, and whether the
pharmacist could access it. Second, difficulties with
interprofessional communication may have discouraged the pharmacist
from calling to seek clarification. Third, the pharmacist may never
have doubted that the prescription was for Synthroid. Drug names
that look alike are easily confused, and a mix-up between Rythmol
and Synthroid is plausible. Fourth, perhaps the physician and/or
pharmacist felt rushed in their environments due to competing
priorities, staffing challenges, or an impatient patient. Poor
lighting, inefficient workflow, or interruptions may have
contributed. Finally, we do not know if the patient was offered
counseling for the "new" medication. If it was offered, he may have
refused it, thinking that his prescription was for his usual
refill. Rythmol 150-mg tablets are white, round, and scored;
Synthroid 150-mcg tablets are light blue, round, partially scored,
and smaller.(20)
The two medications looked dissimilar, and the error could have
been corrected sooner had the patient questioned the pharmacist at
the time of dispensing or shortly thereafter

In this case, the medication
error, a preventable ADE, led to patient harm. Implementing the
necessary system improvements could minimize recurrence of this
type of error. Most importantly, implementation of a CPOE system
would have eliminated prescription illegibility, the precipitating
factor in this case. In addition, three indirect solutions could
contribute to error avoidance: (i) pharmacist access to
patient-specific information in an EMR, or at least the intended
purpose listed on the prescription; (ii) patient counseling at the
point of dispensing; and (iii) patient empowerment to question the
change in prescription in a timely fashion. Finally, if
communication or environmental issues were implicated, these should
be addressed.

Health care systems are adopting systems
approaches to improve patient safety. This, coupled with the
incentives spurring adoption of EMRs and CPOE systems and promoting
their interoperability among settings (21), should result in a marked reduction of this type of
error over time.

Take-Home Points

  • Medication errors are potential adverse
    drug events; medication errors that cause harm are preventable
    adverse drug events. Not all adverse drug events are caused by
    medication errors.
  • Because outpatient ambulatory health
    care delivery is a fragmented process, estimating medication errors
    and adverse drug events in this setting is challenging.
  • Even seemingly simple medication errors
    are multifactorial, involving more than one process and more than
    one line of responsibility.
  • As with medication errors that occur in
    acute care environments, serious ambulatory medication errors
    should also be analyzed from a systems perspective (root cause
    analysis) by members of an interdisciplinary team.
  • Electronic medical records with
    computerized provider order entry systems, when implemented
    correctly, will mitigate certain types of medication errors,
    thereby improving medication safety.

Beth Devine, PharmD,
Research Associate Professor
Pharmaceutical Outcomes Research & Policy Program, School of

Biomedical &
Health Informatics, School of Medicine

University of Washington

Faculty Disclosure: Dr. Devine declares
that she has no financial arrangements or other relationship with
the manufacturers of any commercial products discussed in this
continuing education activity. In addition, her commentary does not
include information regarding investigational or off-label use of
pharmaceutical products or medical devices.


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Figure. Relationship between medication errors
and adverse drug events.(2)