Download Adverse Drug Events – What Do We Really Mean?

Adverse Drug Events – What Do We Really Mean?
Definitions:
 Adverse Drug Event (ADE): Injury resulting from medical
intervention related to a drug (IOM).
 Adverse Drug Reaction (ADR): Any response to a drug
which is noxious and unintended which occurs at doses
normally used in man for prophylaxis, diagnosis, or
therapy of disease, or for the modifications of
physiological function1 (Figure 1).
Relationship between ADE & Medication Errors
An Adverse Drug Event (ADE) is harm associated with any dose
of a drug, whether the dose is “normally used in man” or not. An
Adverse Drug Reaction (ADR) is a subtype of an ADE (i.e., all ADRs are ADEs, but not vice versa) and by definition,
drug-induced harm occurring with appropriate use of medication (i.e., not caused by an error).
While ADEs are medication-related patient injury events,
medication errors encompass all errors that may occur at
any stage of the medication process, with or without
patient harm (Figure 2).
Some ADEs arise as a result of an error and are considered
preventable. Others arise from ADRs, where the
medication is used in a proper manner and are considered
non-preventable ADEs. Potential ADEs (pADEs) are
incidents where patient harm could have occurred, but did
not either because of chance or intervention.2
Adverse Drug Event (ADE): Preventable vs. Non-preventable
Patient Harm
Preventable Harm

1
2
Medication Error that reached patient
Source: World Health Organization (WHO)
Source: Pediatric Drugs. 2009; 11:153-160.
Non-Preventable Harm


Adverse Drug Reaction (ADR)
Allergy
Relationship between Medication Errors and Preventable ADEs (pADEs)
A medication error is 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.
pADEs occurs due to medication errors or mishaps (several definitions state that pADEs are also known as “near
misses” or “close calls”). pADEs are identified medication-related problems (MRPs)/drug-related problems (DRPs)/
medication-therapy problems, these may include, but are not limited to, medication errors.
Drug Therapy Problem Categories
Appropriateness
More effective drug available
pADE
On unnecessary drug therapy
pADE
Does the patient have an indication for
a medication that is not being treated
or prevented?
Needs additional drug therapy
pADE
Lab monitoring needed for screening
pADE
Is the most effective drug product being
used for the medical condition?
Needs different drug
pADE
Lab monitoring needed efficacy
pADE
Dose too low
pADE
Lab monitoring needed for safety
pADE
Undesirable effect
ADE
Contraindication
pADE
Drug interaction
ADE or pADE
Is the dose appropriate and able to
achieve the intended goals of therapy?
Is the patient experiencing an adverse
event from the medication?
Is the dose so high it could cause toxicity
in the patient?
Adherence
ADE/pADE
Is the medication appropriate for the
medical condition being treated?
Effectiveness
Safety
Drug Therapy Problems
Is the patient able to take the medication
as intended?
Dose too high
pADE
Cannot afford
pADE
Forgets to take
pADE
Directions not understood
pADE
Unable to administer correctly
pADE
Patient Case Examples pf pADE and ADE
Patient Story:
MS is a 52-year-old female admitted to the hospital for pneumonia. Her past
medical history includes depression, high cholesterol and high blood pressure.
Her medications include Fluoxetine 20mg, Atorvastatin 40mg, lisinopril 20mg
and warfarin 2.5mg. Upon interviewing the patient, the pharmacist reveals
that MS had had a TKN 5 months ago and that’s when she started taking
warfarin. Following assessment of the patient specific information and the
rest of the medication history, the pharmacist identifies a medication related
problem.
Why is this story a
Medication Error?
Following a TKR warfarin or other
anticoagulant should be
continued for 14 days per ACCP
Chest guidelines
Questions:
What is the medication related problem (pADE)?
What kind of medication error is this?
•
•
•
•
On unnecessary drug therapy
Error in prescribing, communication and monitoring
Answers:
Patient Story:
KW is a 65-year-old male with history of diabetes, dyslipidemia and a recent hospitalization where he was treated
for a pulmonary embolism. Upon discharge, KW was given a new prescription for warfarin 2mg daily, information
for ADR self-monitoring as well as information for a follow up appointment with his PCP. After several doctor visits,
KW’s INR is stabilized at 2.4 (goal 2-3) and since he does not report having any issues, his weekly appointments get
extended to monthly visits. Three months later, KW is hospitalized for complaints of dizziness, lethargy and
shortness of breath. Upon further examination, his labs revealed a therapeutic INR of 2.6 and a low H&H of 7g/dl
and 22% respectively. KW reports proper adherence to his medications and denies any injury leading to bleeding. A
stool guaiac test is performed and comes back positive.
Questions:
What kind of medication-related patient harm is this?
Answers:
• Non-preventable; ADR
•
Patient Story:
PR is a 78-year-old female nursing home resident with history of high blood
pressure. PR started complaining of pain in her lower back from an injury she
sustained in the past. She describes her pain as sharp stabs and rates it as a 9
in a 0-10 scale. PR denies any previous history of opioid use having controlled
her sporadic pain with Tylenol and Advil. Unfortunately her pain is now
uncontrollable and her doctor prescribes Fentanyl patch 12.5 mg. One week
after the new pain medication was started, the nursing home staff notices
difficulty swallowing and increased altered mental status.
Why is this story a
Medication Error?
Initiating the use of long-acting
opioids (LAOs) in opioid-naïve
individuals (those who have
never taken opioids) has been
highlighted by the U.S. Food and
Drug Administration (FDA) as a
potentially dangerous practice
Questions:
What kind of medication-related patient harm is this?
What kind of medication error is this?
•
•
On unnecessary drug therapy
Error in prescribing and monitoring
Answers:
•
•
Patient Story:
JM is a 66-year-old female who was recently discharged home after a long
stay in ICU and subsequent rehab. Her medication list prior to admission
included amiodarone 200mg daily atorvastatin 40mg daily, Lisinopril 10mg
daily and glyburide 5mg twice daily. Upon admission to ICU her glyburide was
discontinued and intensive insulin therapy was started. She was subsequently
discharged on insulin sliding scale.
It has now been a few months since her rehab stay and JM presents to her
doctor’s office with complaints of dizziness, clamminess and an episode of
fainting which did not result in a fall. Upon review of the medication list, it is
found that JM continued to take her glyburide 5mg twice daily in conjunction
with her newly prescribed insulin.
Why is this story a
Medication Error?
Hyperglycemia frequently occurs
with acute medical illness,
especially among patients with
cardiovascular disease. This has
been linked to increased
morbidity and mortality in
critically ill patients.
An expanding body of literature
describes the benefits of
normalizing hyperglycemia with
insulin therapy in hospitalized
patients
Questions:
What kind of medication-related patient harm is this?
What kind of medication error is this?
•
•
•
•
On unnecessary drug therapy
Error in communication
Answers:
This material was prepared by the New England Quality Innovation Network-Quality Improvement Organization (NE QIN-QIO), the Medicare Quality
Improvement Organization for New England, under contract with the Centers for Medicare & Medicaid Services (CMS), an agency of the U.S. Department of
Health and Human Services. The contents presented do not necessarily reflect CMS policy. CMSQIN_C3-2_201508_0174