308
P A R T 4
Drugs acting on the central and peripheral nervous systems
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■
Assess for baseline status before beginning therapy
to check for occurrence of any potential adverse
effects
. Assess for the following: temperature and
weight; skin colour and lesions; affect, orientation,
reflexes and vision; pulse, blood pressure and
perfusion; respiratory rate, adventitious sounds and
presence of chronic pulmonary disease; and bowel
sounds on abdominal examination.
■
■
Perform laboratory tests, including renal and liver
function tests and full blood count (FBC).
Refer to the Critical thinking scenario for a full
discussion of care for a person dealing with anxiety
.
Implementation with rationale
■
■
Do not administer intra-arterially
because serious
arteriospasm and gangrene could occur
. Monitor
injection sites carefully for local reactions to
institute treatment as soon as possible.
■
■
Do not mix intravenous (IV) drugs in solution
with any other drugs
to avoid potential drug–drug
interactions
.
■
■
Give parenteral forms only if oral forms are not
feasible or available, and switch to oral forms,
which are safer and less likely to cause adverse
effects
, as soon as possible.
■
■
Give IV drugs slowly
because these agents have
been associated with hypotension, bradycardia
and cardiac arrest
.
■
■
Arrange to reduce the dose of narcotic analgesics
in people receiving a benzodiazepine
to decrease
potentiated effects and sedation
.
■
■
Maintain people who receive parenteral
benzodiazepines in bed for a period of at least
3 hours. Do not permit ambulatory people to
operate a motor vehicle after an injection
to ensure
safety
.
■
■
Monitor hepatic and renal function, as well
as FBC, during long-term therapy
to detect
dysfunction and to arrange to taper and
discontinue the drug if dysfunction occurs
.
■
■
Taper dose gradually after long-term therapy,
especially in epileptic individuals.
Acute
withdrawal could precipitate seizures in these
people. It may also cause withdrawal syndrome
.
■
■
Provide comfort measures
to help people
tolerate drug effects
, such as having them void
before dosing, instituting a bowel program as
needed, giving food with the drug if GI upset
is severe, providing environmental control
(lighting, temperature, stimulation), taking safety
precautions (use of side rails, assistance with
ambulation) and aiding orientation.
■
■
Provide thorough teaching, including drug name,
prescribed dose, measures for avoidance of adverse
effects and warning signs that may indicate
possible problems. Instruct people about the need
for periodic monitoring and evaluation
to enhance
knowledge about drug therapy and to promote
compliance
.
■
■
Offer support and encouragement
to help the
person cope with the diagnosis and the drug
regimen
.
■
■
If necessary, use flumazenil (Box 20.3), the
benzodiazepine antidote,
for the treatment of
overdose
.
Evaluation
■
■
Monitor response to the drug (alleviation of signs
and symptoms of anxiety; sleep; sedation).
■
■
Monitor for adverse effects (sedation, hypotension,
cardiac arrhythmias, hepatic or renal dysfunction,
blood dyscrasias).
■
■
Evaluate the effectiveness of the teaching plan
(person can give the drug name, dosage, possible
adverse effects to watch for, specific measures to
help avoid adverse effects and the importance of
continued follow-up).
■
■
Monitor the effectiveness of comfort measures and
compliance with the regimen.
Flumazenil (
Anexate
), a benzodiazepine antidote, acts
by inhibiting the effects of the benzodiazepines at the
gamma-aminobutyric acid (GABA) receptors. It is used
for three purposes: to treat benzodiazepine overdose, to
reverse the sedation caused by benzodiazepines that are
used as adjuncts for general anaesthesia, and to reverse
sedation produced for diagnostic tests or other medical
procedures.
Flumazenil, which is available for IV use only, is
injected into the tubing of a running IV. The drug has
a rapid onset of action that peaks 5 to 10 minutes after
administration. It is metabolised in the liver. Because
this drug has a half-life of about 1 hour, it may be
necessary to repeat injections of flumazenil if a long-
acting benzodiazepine was used.
People who receive flumazenil should be monitored
continually, and life-support equipment should be
readily available. If the person has been taking a
benzodiazepine for a long period, administration of
flumazenil may precipitate a rapid withdrawal syndrome
that necessitates supportive measures. Headache,
dizziness, vertigo, nausea and vomiting may be
associated with use of flumazenil.
■■
BOX 20.3
A benzodiazepine antidote
