Our May 5, 2015
Patient Safety Tip of the Week “Errors
with Oral Oncology Drugs” pointed out that, with the recent proliferation
of oral chemotherapy agents, we are beginning to see more and more patient safety
issues arising from their use. One facet we only briefly touched upon in that
column was the use of independent double checks.
One of our most
frequently accessed columns is our October 16, 2012 Patient Safety Tip of the
Week “What
is the Evidence on Double Checks?”. Usually when
we are talking about independent double checks we are referring to such checks
being done at the same stage of the medication continuum (eg.
during ordering or during preparation). But medication safety also includes
another type of independent double check at several levels. For example, in a
hospital medications ordered by a physician or other prescriber are typically
checked by a pharmacist and nurse at different times. In our November 3, 2015
Patient Safety Tip of the Week “Medication
Errors in the OR – Part 2” we noted one of the reasons for more medication
errors in the OR is that the anesthetist is often the one choosing a
medication, preparing it, and administering it, thereby lacking those
independent checks that might occur elsewhere.
While we’ve pointed
out the limitations of double checks in several columns, we still recommend
independent double checks for high alert drugs. In the hospital, chemotherapy
agents are high alert drugs that get such attention. But what happens outside
the hospital? Particularly as more and more oral chemotherapy agents are being
developed and used, do they get the same degree of scrutiny that is typically
done for IV chemotherapy agents? A new study (Griffin
2015) suggests no. Griffin and colleagues in Canada compared the
performance of independent double checks for oral vs. intravenous chemotherapy
and found striking differences. Using direct observation by two human factors
experts and semi-structured interviews they found 57 systematic checks for IV
chemotherapy compared to only 6 for oral chemotherapy. Systematic checks
required the check be done clearly as a part of a qualified healthcare
provider’s (HCP) role, be done consistently, and be done with all the
information necessary to inform such a check. They defined “partial” checks if
one of those elements was missing. Even when they included “partial” checks,
the results were 64 checks for IV chemotherapy vs. only 17 for oral
chemotherapy.
For IV chemotherapy there were checks at multiple levels
(planning, ordering, and dispensing). So for IV chemotherapy there were several
opportunities for a qualified HCP to identify and mitigate an unintentional
error before it reached the patient. Not so for oral chemotherapy. Often the
only qualified HCP with an opportunity to intercept an error was the community
pharmacist and these were in the ordering and dispensing phases only. And those
community pharmacists were often lacking critical information. They often did
not even have access to critical information such as the type of cancer the
patient had.
Though this was a
Canadian study, the authors cite studies from the US (Weingart 2007)
that showed few of the
safeguards routinely used for infusion chemotherapy have been adopted for oral
chemotherapy at US cancer centers and lack of consensus at these centers about
safe medication practices for oral chemotherapy.
In our May 5, 2015
Patient Safety Tip of the Week “Errors
with Oral Oncology Drugs” we discussed an analysis of incidents involving
oral chemotherapy agents in Canada (ISMP
Canada 2015). They analyzed 516 incidents over a 12 year period and while
patient harm or death occurred in only a small minority of cases there were
multiple lessons learned. They were able to identify 3 major themes: (1)
lack of specialized knowledge by care providers (2) medication name mix-ups and
(3) lack of safe medication handling processes. Under the first theme ISMP
Canada noted that chemotherapy regimens can be very complex and that community
pharmacists may not have a good understanding of chemotherapy cycles,
side-effect profiles, etc. The same applies to many other non-oncologist
healthcare professionals. As a result, patient education on these complex
issues may be insufficient. The example they provide is a patient who was on a
protocol-defined capecitabine cyclical dosing regimen
who was mistakenly given capecitabine daily when
admitted as an inpatient and then the prescription given the patient at
discharge also erroneously called for daily capecitabine.
You may recognize this problem of prescribing a drug daily rather than on a
different regimen because we’ve written about very similar problems with
methotrexate in the past (see our What’s New in the Patient Safety World
columns for July 2010 “Methotrexate
Overdose Due to Prescribing Error” and July 2011 “More
Problems with Methotrexate” and February 2016 “Avoiding
Methotrexate Errors”).
As a subtheme of the
“lack of specialized knowledge” they mention that failure to include some
critical information on the prescriptions may contribute. Such information
might include diagnosis, patient height and weight, duration of the
chemotherapy cycle, etc.
We also cited a
classic article on medication errors related to oral chemotherapy (Weingart
2010). Weingart and colleagues warned that
the use of oral chemotherapy was expanding and that few of the safeguards that
apply to prescribing, dispensing and administering IV chemotherapy have been
applied to oral chemotherapy. They identified issues with oral chemotherapy
from a variety of sources. They identified over 500 such errors, including 99
actual adverse drug events. While many of the remaining events were near-misses
they did provide the opportunity for patient harm and thus were helpful in
identifying potential vulnerabilities. Importantly, they identified that over
half the errors (55.9%) were intercepted, preventing actual patient harm. Of
those intercepted, this was most often by a pharmacist (69.5%), followed by
patient or family (10.2%) or nurse (6.9%). Wrong dose errors were most frequent
but wrong drug and missed dose errors also occurred. But one particularly
salient problem was supplying the wrong number of days. Whereas the
majority of errors involving wrong dose, wrong drug, or missed dose resulted in
near misses, 39.3% of errors involving wrong number of days supplied resulted
in adverse drug events. We went on in that column to discuss several other
instances of pharmacies supplying the wrong number of days or doses for oral
chemotherapy.
So now that we’ve identified lack of double checks as a
vulnerability for oral chemotherapy, how do we address it? One is to ensure
that a pharmacist with access to all critical clinical information and a
thorough understanding of both the particular cancer and the chemotherapy
regimen is involved as a potential double checker. Unfortunately, this may mean
that some community pharmacists and mail order pharmacies are not the most
appropriate for patients on oral chemotherapy regimens. Anyone who has picked
up a prescription at a community pharmacy will recognize how busy the
pharmacist is, further increasing the vulnerability to errors. And very often
there is only a single pharmacist working. So there is no opportunity for a
double check. The only barrier left to intercept the error is the patient
him/herself (or their family/caregiver). So one consideration would be to
ensure that prescriptions for oral chemotherapy are only dispensed in certain
pharmacies that meet all the safety requirements. Such pharmacies would most
likely hospital- or clinic-based but some community pharmacies would be
eligible if they met those criteria. That may also require various payors to ensure that such special pharmacies are included
in their networks. Since the criteria should include not only ability to
perform double checks but also have full access to relevant clinical
information, knowledge about the various chemotherapy regimens, and ability to
sit down with the patient to thoroughly go over the instructions, we doubt that
mail order pharmacies would meet the criteria.
Secondly, recognizing that complex regimens and cycles are
the most vulnerable to errors involving wrong number of day supplies, we need
to look at how we prescribe. We are always balancing patient convenience
against patient safety. In several of our previous columns on home infusion
chemotherapy we noted no one seemed to be asking “what is the highest dose that
a patient could tolerate in one day (or less) if there was inadvertent
administration of the infusion?”. A safety culture
would design the protocol with sublethal dosages that
would protect the patient in the event of “what can go wrong will go wrong”. It
also would not put the healthcare workers at the “sharp end” in a situation
none of us would want to be in. The same question should apply to oral
chemotherapy regimens and be “What would be the highest aggregate dose a patient
could tolerate over a specified period?” and avoid prescribing more than that
inadvertently. Yes, the patient might be inconvenienced by having to do another
physician or clinic visit to get a prescription for the next cycle or the
second part of a complex regimen. But isn’t that preferable to receiving a
chemotherapy overdose due to an avoidable error?
Our prior columns related to chemotherapy safety:
References:
Griffin MC, Gilbert RE, Broadfield
LH, et al. Comparison of Independent Error Checks for Oral Versus
Intravenous Chemotherapy. Journal of Oncology Practice 2015;
Published online before print September 29, 2015
Weingart SN, Flug
J, Brouillard D, et al. Oral chemotherapy safety
practices at US cancer centres: questionnaire survey.
BMJ 2007; 334: 407
http://www.bmj.com/content/334/7590/407
ISMP Canada. Analysis of Incidents Involving Oral
Chemotherapy Agents. ISMP Canada Safety Bulletin 2015; 15(4): 1-4, April 22,
2015
http://www.ismp-canada.org/download/safetyBulletins/2015/ISMPCSB2015-04_OralChemotherapyAgents.pdf
Weingart SN, Toro J, Spencer J, et
al. Medication errors involving oral chemotherapy. Cancer 2010; 116(10):
2455-2464
http://onlinelibrary.wiley.com/doi/10.1002/cncr.25027/full
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