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P A R T 4
Drugs acting on the central and peripheral nervous systems
In addition, because of an enzyme-induction effect
of barbiturates in the liver, the following drugs may not
be as effective as desired: oral anticoagulants, digoxin,
tricyclic antidepressants (TCAs), corticosteroids, oral
contraceptives, oestrogens, paracetamol, metronidazole,
carbamazepine, beta-blockers, griseofulvin, phenyl
butazones, theophyllines, quinidine and doxycycline.
If these agents are given in combination with barbitu-
rates, people should be monitored closely; frequent dose
adjustments may be necessary to achieve the desired
therapeutic effect.
■■
Barbiturates are an older class of drugs used as
anxiolytics, sedatives and hypnotics. Because they
are associated with potentially serious adverse
effects and interact with many other drugs, they
are less desirable than the benzodiazepines or other
anxiolytics.
OTHER ANXIOLYTIC AND HYPNOTIC
DRUGS
Other drugs are used to treat anxiety or to produce
hypnosis that do not fall into either the benzodiaze-
pine or the barbiturate group. See Table 20.3 for a list
of other anxiolytic/hypnotic drugs, including usual
KEY POINTS
Care considerations for
people receiving barbiturates
Assessment: History and examination
■
■
Assess for contraindications or cautions: known
allergies to barbiturates
to prevent hypersensitivity
reactions
or a history of addiction to sedative/
hypnotic drugs
to avert a similar problem with
these drugs
; impaired hepatic or renal function
that could alter the metabolism and excretion
of the drug
; cardiac dysfunction or respiratory
dysfunction; seizure disorders,
which could be
exacerbated by these drugs
; acute or chronic pain
disorders,
which should be evaluated before using
these drugs
; and pregnancy or breastfeeding,
which
would indicate a need for caution when using
these drugs
.
■
■
Assess for baseline status
before beginning
therapy and for the occurrence of any potential
adverse effects
. Assess the following: temperature
and weight; blood pressure and pulse, including
perfusion; skin colour and lesions; affect,
orientation and reflexes; respiratory rate and
adventitious sounds; and bowel sounds.
Implementation with rationale
■
■
Do not administer these drugs intra-arterially
because serious arteriospasm and gangrene could
occur
. Monitor injection sites carefully
for local
reactions
.
■
■
Do not mix 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
as soon as possible
to avoid serious reactions or
adverse effects
.
■
■
Give IV medications slowly
because rapid
administration may cause cardiac problems
.
■
■
Provide standby life-support facilities
in case of
severe respiratory depression or hypersensitivity
reactions
.
■
■
Taper dose gradually after long-term therapy,
especially in people with epilepsy. Acute
withdrawal
may precipitate seizures or cause
withdrawal syndrome in these individuals
.
■
■
Provide comfort measures
to help people tolerate
drug effects
, including small, frequent meals; access
to bathroom facilities; bowel program as needed;
consuming food with the drug if GI upset is severe;
and environmental control, safety precautions,
orientation and appropriate skin care as needed.
■
■
Provide thorough teaching, including drug name,
prescribed dosage, 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
.
Evaluation
■
■
Monitor response to the drug (alleviation of
signs and symptoms of anxiety, sleep, sedation,
reduction in seizure activity).
■
■
Monitor for adverse effects (sedation, hypotension,
cardiac arrhythmias, hepatic or renal dysfunction,
skin reactions, dependence).
■
■
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.
