Nurse and pharmacist resolve oral-to-IV dosing conflict
From the January 12, 2006 issue
Doses of some medications need to be
adjusted when converting from one route
of administration to another, as demonstrated
in the following reported event. A
physician ordered metoprolol 50 mg IV
for a patient, ten times more than the
normal IV dose for this beta-blocker. He
was unaware of the vast difference
between the safe oral and parenteral dose.
Fortunately, an experienced nurse and
pharmacist immediately intervened.
However, we are aware of cases in which
fatal overdoses were ordered and administered
under similar circumstances.
In our February 25, 1998 newsletter, we
published a case about a child with
myasthenia gravis who had oral neostigmine
switched to a parenteral form
without proper dose adjustment. Unaware
that the dose should be adjusted, her
physician ordered the same dose she had
been taking orally. Pharmacists and nurses
did not recognize the overdose, which led
to the child’s death.
An abbreviated list of drugs with oral and
IV dose differences appears in Table 1 to
illustrate just how different these doses
can be. Without knowledgeable staff and
computer dose warnings, dosing errors are
likely because textbook and label warnings
about the need for dose adjustments are
often inadequate or nonexistent.
Incidentally, the reporter of the recent
metoprolol error told us that the ordering
physician initially refused to change the
dose and told the nurse to “Just give it.”
The nurse felt that the dose could harm
the patient and refused. Independently, a
pharmacist called the physician, also to
request a dose change. The request was
similarly denied but, after telling the
physician that the ordered IV dose of this
beta-blocker was quite different from the
oral dose and would likely be fatal, the
doctor discontinued his original order and
prescribed the correct dose.
Fortunately, these professionals stood
their ground, likely preventing serious
patient harm. But a 2004 ISMP study on
workplace intimidation revealed that
almost half of more than 2,000 healthcare
providers from hospitals indicated that
their past experiences with intimidation
had altered the way they handle order
clarifications (Smetzer JL, Cohen MR.
Intimidation: practitioners speak up about
this unresolved problem. Joint Com J Qual
Patient Safety 2005; 31: 594-99). As a
result, 7% of respondents reported that
they had been involved in a medication
error in which intimidation played a role.
Recommendations for resolving conflicts
in drug therapy are available on our