Acetaminophen (N-Acetyl-p-Aminophenol; APAP)

Email

Send Email

Recipient(s) will receive an email with a link to 'Acetaminophen (N-Acetyl-p-Aminophenol; APAP)' and will have access to the topic for 7 days.

Subject: Acetaminophen (N-Acetyl-p-Aminophenol; APAP)

(Optional message may have a maximum of 1000 characters.)

×


Definition

  • Nonopioid analgesic, antipyretic

Use

  • Relief of pain, such as headaches and toothaches

  • Reduction of fever

Interpretation

  • Screen of urine: indication of exposure

  • Screen of serum: used to assess potential toxicity

  • Normal range: 5–20 μg/mL serum

  • Potentially toxic: >150 μg/mL measured 4 hours postdose

Limitations

  • Screening

    • Serum/urine: colorimetric or immunoassay on automated chemistry analyzers

      • High bilirubin concentrations [>50 μg/mL] may cause false-positive results with immunoassay-based tests.

      • Plasma may be tested in place of serum. Anticoagulants such as EDTA and heparin do not generally interfere with the assay.

      • Do not use whole blood.

  • Confirmation:

    • Serum/urine–HPLC or GC/MC

    • APAP is highly conjugated by glucuronidation and sulfation.

    • An assay that includes a hydrolysis step provides total APAP levels, which are not useful for assessing toxicity.

 
×