Hospital Pharmacy - July/August 2018 - 219

219

Cohen and Smetzer
"rapid-acting" stickers on the containers could also help differentiate the products. As insulin does not need to be kept in
the refrigerator once it has been opened, it may also be helpful
to instruct patients to keep their long-acting, bedtime insulin
pen in the bedroom, and their rapid-acting, mealtime insulin
pen in the kitchen or dining room. However, relying totally on
where a medicine is stored is risky and can lead to an error,
especially if a spouse moves the insulin around.

Look-Alike Name Pair-VoLumen and
Voluven
An obstetrical patient received oral VOLUMEN (barium
sulfate suspension, E-Z-EM [subsidiary of Bracco]) instead
of intravenous (IV) fluid resuscitation with VOLUVEN (tetrastarch, hydroxyethyl starch in sodium chloride injection,
Hospira). One might assume that such an error must be next
to impossible given the different routes of administration, the
typical dose of oral barium sulfate, and the fact that imaging
of the gastrointestinal (GI) tract had not been ordered.
However, here is how the error happened.
In deciding what to order for fluid resuscitation, the
patient's obstetrician consulted with a certified registered
nurse anesthetist (CRNA) who recommended Voluven. The
obstetrician then typed "V-O-L-U" in the computer order
entry system, and VoLumen popped up. Subsequently, 500
mL of VoLumen was ordered instead of the intended Voluven.
A hospital pharmacist soon called the prescriber to confirm
the odd request, but the prescriber insisted that the drug was
what the CRNA told him to order. The pharmacist then called
the CRNA on call, but due to a language barrier and unfamiliarity with VoLumen, the CRNA thought the pharmacist was
asking about Voluven and stated that it was fine to use this
medication. The patient received the entire 500 mL of oral
barium (orally) and fortunately suffered no adverse effects
other than delaying her overall care.
When clarifying orders, encourage practitioners to use a
standard format that helps to ensure clarity of communication (eg, SBAR), which includes an assessment of the concern. In this case, asking whether the patient was scheduled
for GI imaging might have clarified the issue with the prescriber and the CRNA. The hospital added these medications
to its look-alike, sound-alike drug name list and made

modifications in the electronic prescribing system to alert
providers when one or the other is ordered. ISMP has contacted each manufacturer as well as the US FDA to consider
the need for a name change for one of these products.

Severe Under Dosing of Insulin With
U-500 Pen
An emergency department (ED) pharmacist was talking to a
patient about his U-500 insulin dose. The patient, who had
been using a U-500 insulin pen, told the pharmacist that his
dose was 75 units but proceeded to show the pharmacist
how he turned the dose knob on the pen to "15" to deliver
each dose. The patient thought his physician had told him to
dial to "15" to deliver 75 units. Prior to using the U-500 pen,
the patient used a U-100 syringe to measure each dose of
75 units from a vial of U-500 insulin. Before U-500 syringes
or pens were available, patients using U-500 insulin were
commonly taught to use a U-100 insulin syringe and to measure their dose in "syringe units," meaning the U-100 scale
was used for dose measurement, but the actual dose was 5
times more than the measured dose. Thus, the patient had
been drawing up the U-500 insulin into the U-100 syringe to
the "15" units marking. The patient was then shown how to
deliver the correct dose by dialing the U-500 insulin pen to
75 units.
Even with the availability of U-500 insulin pens, patient
and provider confusion about the dose may still occur, especially when patients previously relied on a U-100 syringe to
inject U-500 insulin. Dangerous under dosing with a U-500
pen should be considered in patients who exhibit severe
hyperglycemia or diabetic ketoacidosis. For U-500 insulin,
ISMP recommends using a U-500 insulin pen or a U-500
insulin syringe. Unfortunately, patients still use U-100
syringes with U-500 insulin, thus risking confusion.
References
1.

Yin HS, Parker RM, Sanders LM, et al. Liquid medication
errors and dosing tools: a randomized controlled experiment.
Pediatrics. 2016;138:e20160357.
Yin HS, Parker RM, Sanders LM, et al. Pictograms, units and
dosing tools, and parent medication errors: a randomized study.
Pediatrics. 2017;140:e20163237.

Table of Contents for the Digital Edition of Hospital Pharmacy - July/August 2018