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Patient Care - NarcoticsNarcotics
General comments.
Narcotics are used for the treatment of severe pain and for the control of
severe cough and diarrhea.
Dyspnea caused by acute left ventricular failure is frequently
relieved by morphine. About a dozen narcotics are commonly employed. The common
errors that occur with the use of narcotics (particularly with meperidine)
include underestimation of the amount of narcotic required for pain relief,
overestimation of the duration of action, and possibly an exaggerated
estimation of the dangers of addiction for medical inpatients.
2.
Pharmacologic actions, in addition to analgesia, include respiratory and
circulatory
depression, sedation, alteration of mood, bronchospasm, increase
in sphincter
tone, atony of the bowel, nausea and vomiting, antidiuresis,
addiction,
and, rarely, true allergic reactions, which may account
for episodes of "sudden death" from pulmonary edema among addicts.
Tachyphylaxis
usually occurs. There are probably no major differences
in the adverse effects of various narcotics when given in
equianalgesic
doses, but an individual patient will usually tolerate one
drug better
than another.
3. Clinical use and precautions:
a) Narcotics should not be used when other drugs or physical
measures
will provide relief of pain. They should not be prescribed for
longer
than 24-48 hours at a time, except in patients with far-advanced
cancer.
They
are most effective parenterally. They should be used
cautiously in patients who experience euphoria as well as relief of
pain,for
these patients may be particularly susceptible to habituation
or addiction.
More
stable patients do not become physiologically dependent
on a narcotic until after it has been given for 2 weeks or
longer,
but habituation may occur more quickly. The hazard of addiction
should not
preclude long-term administration of narcotics to patients
with terminal
cancer.
b) Narcotics are contraindicated in certain acute disease states
(e.g.,
suspected surgical abdomen) in which the pattern and degree of pain
are
important diagnostic signs, as well as in patients with suspected
acute head
injuries, for their administration will prevent accurate
assessment of neurologic changes.
c) Narcotic-induced vomiting may often be avoided by giving a small
dose
(to depress the vomiting center) before the planned therapeutic
dose. Side
effects may also be reduced by keeping the patient recumbent.
d) Hydroxyzine
pamoate (Vistaril), in doses of 25-50 mg 1M, has been
shown to potentiate the effect of a given dose of a narcotic and
will
reduce the frequency of 1M injections. It also has antiemetic
properties.
e) Narcotics depress the respiratory center, and the effect is
directly proportional to the dose. Therapeutic doses diminish both tidal volume
and
respiratory rate. (The response to hypercapnia, but not to
hypoxia, is
usually the stimulus for respiration. Oxygen should thus
be given cautiously.) Narcotics should be used cautiously in
patients
with pulmonary insufficiency and in those taking phenothiazine
derivatives. Bonchospasm
may occur, particularly in patients with a history of asthma.
f) Narcotics
increase sphincter tone in the GI tract, biliary tract, ureters,
and urinary
bladder. They should be given with great care to patients
with biliary
colic, fulminant ulcerative colitis, and prostatic hypertrophy.
Transient
elevation of serum amylase may follow the administration
of morphine. Narcotics markedly decrease propulsive contractions
in the
bowel by producing hypertonic delay of peristalsis.
g) Narcotics impair reflex activity from receptors in the aortic
arch,
carotid sinus, and pulmonary vessels and may occasionally produce
orthostatic
hypotension, syncope, peripheral vasodilatation, and circulatory
collapse.
Bradycardia, can be reversed with atropine,. h)
Narcotics should be used with extreme caution in patients with hypothyroidism,
Addison's disease, hypopituitarism, anemia, reduced
blood volume, head trauma, asthma, severe malnutrition, or
debilitation.
In patients with increased intracranial pressure, narcotics may
further
elevate cerebrospinal fluid pressure.
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