This page shows results related to Acetaminophen and Drug Ineffective from the FDA Adverse Event Reporting System (AERS).Click here to learn about all Acetaminophen adverse events.
The Naranjo Scale is a questionnaire for determining the likelihood of whether an adverse drug reaction is actually due to the drug or caused by other factors. Probability is assigned via a score termed definite, probable, possible or doubtful.*
|Are there previous conclusive reports on this reaction?|
|Did the adverse event appear after the suspected drug was administered?|
|Did the adverse reaction improve when the drug was discontinued or a specific antagonist was administered?|
|Did the adverse reaction reappear when the drug was readministered?|
|Are there alternative causes (other than the drug) that could on their own have caused the reaction?|
|Did the reaction reappear when a placebo was given?|
|Was the drug detected in the blood (or other fluids) in concentrations known to be toxic?|
|Was the reaction more severe when the dose was increased, or less severe when the dose was decreased?|
|Did the patient have a similar reaction to the same or similar drugs in any previous exposure?|
|Was the adverse event confirmed by any objective evidence?|
*Naranjo, et al. "A method for estimating the probability of adverse drug reactions." Clin Pharmacol Ther. 1981 Aug;30(2):239-45.
To learn more about all adverse events for Acetaminophen, view the complete Acetaminophen adverse event report.
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