What is the rate of adverse events after oral N-acetylcysteine administered by the intravenous route to patients with suspected acetaminophen poisoning?
OBJECTIVE
We conduct a study to determine the rate of adverse events (anaphylactoid and cardiorespiratory) associated with the use of oral N-acetylcysteine by the intravenous route for the treatment of suspected acetaminophen poisoning and to examine specific variables that may be associated with adverse events.


METHODS
We conducted a retrospective medical record review with explicit criteria. All patients who received oral N-acetylcysteine by the intravenous route from September 1995 to September 2001 were included. Patients were identified by cross-matching 3 databases. Adverse events were divided into categories of cutaneous, systemic, or life threatening. Five reviewers abstracted charts by using a standardized data collection form. Interrater reliability was calculated by using 24 medical records abstracted by all 5 reviewers.


RESULTS
There were 7 adverse events identified in 187 patients (3.7%; 95% confidence interval 1.0% to 6.5%). Six adverse events were cutaneous and responded rapidly to antihistamines. One adverse event was life threatening but not clearly related to N-acetylcysteine. A high rate of antihistamine exposure (53%) was identified before the administration of N-acetylcysteine. Interrater agreement was higher than 95%.


CONCLUSIONS
Intravenous administration of an oral solution of N-acetylcysteine is associated with a low rate of adverse events and should be considered for selected patients with suspected acetaminophen poisoning.
Kao
Louise W
LW
Indiana Poison Center, Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis 46206, USA. Lkao@clarian.org
Kirk
Mark A
MA
Furbee
R Brent
RB
Mehta
Nimish H
NH
Skinner
Jason R
JR
Brizendine
Edward J
EJ
D000082:Acetaminophen / Q000506:poisoning*; D000111:Acetylcysteine / Q000008:administration & dosage* / Q000009:adverse effects*; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000707:Anaphylaxis / Q000453:epidemiology*; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D003875:Drug Eruptions / Q000453:epidemiology / Q000209:etiology; D004342:Drug Hypersensitivity / Q000453:epidemiology* / Q000209:etiology; D004347:Drug Interactions; D062787:Drug Overdose; D005260:Female; D016166:Free Radical Scavengers / Q000008:administration & dosage* / Q000009:adverse effects*; D006634:Histamine H1 Antagonists / Q000627:therapeutic use; D006801:Humans; D007196:Indiana / Q000453:epidemiology; D007223:Infant; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D012140:Respiratory Tract Diseases / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D016019:Survival Analysis
D016166:Free Radical Scavengers; D006634:Histamine H1 Antagonists; D000082:Acetaminophen; D000111:Acetylcysteine