Signs and Symptoms: In acute acetaminophen overdosage, dose-dependent
potentially fatal hepatic necrosis is the most serious adverse effect. Renal
tubular necrosis, hypoglycemic coma and thrombocytopenia may also occur.
In adults, hepatic toxicity has rarely been reported with acute overdoses of less than 10 grams and fatalities with less than 15 grams. Importantly, young children seem to be more resistant than adults to the hepatotoxic effect of an acetaminophen overdose. Despite this, the measures outlined below should be initiated in any adult or child suspected of having ingested an acetaminophen overdose.
Early symptoms following a potentially hepatotoxic overdose may include: nausea, vomiting, diaphoresis and general malaise. Clinical and laboratory evidence of hepatic toxicity may not be apparent until 48 to 72 hours post-ingestion.
Treatment: The stomach should be emptied promptly by lavage or
by induction of emesis with syrup of ipecac. Patients' estimates of the quantity
of a drug ingested are notoriously unreliable. Therefore, if an acetaminophen
overdose is suspected, a serum acetaminophen assay should be obtained as early
as possible, but no sooner than four hours following ingestion. Liver function
studies should be obtained initially and repeated at 24-hour intervals.
The antidote, N-acetylcysteine, should be administered as early as possible, and within 16 hours of the overdose ingestion for optimal results. Following recovery, there are no residual, structural, or functional hepatic abnormalities.
Signs and Symptoms: Serious overdosage with oxycodone is characterized
by respiratory depression (a decrease in respiratory rate and/or tidal volume,
Cheyne-Stokes respiration, cyanosis), extreme somnolence progressing to stupor
or coma, skeletal muscle flaccidity, cold and clammy skin, and sometimes bradycardia
and hypotension. In severe overdosage, apnea, circulatory collapse, cardiac
arrest and death may occur.
Treatment: Primary attention should be given to the reestablishment
of adequate respiratory exchange through provision of a patent airway and the
institution of assisted or controlled ventilation. The narcotic antagonist naloxone
hydrochloride is a specific antidote against respiratory depression which may
result from overdosage or unusual sensitivity to narcotics, including oxycodone.
Therefore, an appropriate dose of naloxone hydrochloride (usual initial adult
dose 0.4 mg to 2 mg) should be administered preferably by the intravenous route
and simultaneously with efforts at respiratory resuscitation (see package
insert). Since the duration of action of oxycodone may exceed that of the
antagonist, the patient should be kept under continued surveillance and repeated
doses of the antagonist should be administered as needed to maintain adequate
An antagonist should not be administered in the absence of clinically significant respiratory or cardiovascular depression. Oxygen, intravenous fluids, vasopressors and other supportive measures should be employed as indicated.
Gastric emptying may be useful in removing unabsorbed drug.
TYLOX (oxycodone and acetaminophen capsules) should not be administered to patients who are hypersensitive to any component.