10 OVERDOSAGE
10.1 Symptoms
Acute overdosage with morphine is manifested by respiratory
depression, somnolence progressing to stupor or coma, skeletal muscle
flaccidity, cold and clammy skin, constricted pupils, and, sometimes, pulmonary
edema, bradycardia, hypotension, and death. Marked mydriasis rather than miosis
may be seen due to severe hypoxia in overdose situations.
10.2 Treatment
Primary attention should be given to the re-establishment of a
patent and protected airway and institution of assisted or controlled
ventilation if needed. Other supportive measures (including oxygen,
vasopressors) should be employed in the management of circulatory shock and
pulmonary edema accompanying overdose as indicated. Cardiac arrest or
arrhythmias will require advanced life support techniques.
The pure opioid antagonists, naloxone or nalmefene, are specific antidotes to
respiratory depression which results from opioid overdose. Since the duration of
reversal would be expected to be less than the duration of action of morphine in
EMBEDA, the patient must be carefully monitored until spontaneous respiration is
reliably re-established. EMBEDA will continue to release and add to the morphine
load for up to 24 hours after administration and the management of an overdose
should be monitored accordingly. If the response to opioid antagonists is
suboptimal or not sustained, additional antagonist should be given as directed
by the manufacturer of the product.
Opioid antagonists should not be administered in the absence of clinically
significant respiratory or circulatory depression secondary to morphine
overdose. Such agents should be administered cautiously to persons who are
known, or suspected to be physically dependent on EMBEDA. In such cases, an
abrupt or complete reversal of opioid effects may precipitate an acute
withdrawal syndrome.
The sequestered naltrexone in EMBEDA has no role in the treatment of opioid
overdose.
In an individual physically dependent on opioids, administration of an opioid
receptor antagonist may precipitate an acute withdrawal. The severity of the
withdrawal produced will depend on the degree of physical dependence and the
dose of the antagonist administered. Use of an opioid antagonist should be
reserved for cases where such treatment is clearly needed. If it is necessary to
treat serious respiratory depression in the physically dependent patient,
administration of the antagonist should be begun with care and by titration with
smaller than usual doses of the antagonist
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