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Test Code 1005 Acetaminophen, Plasma

Performing Laboratory

Barnes-Jewish Hospital Laboratory


Enzymatic Colorimetric
Note: This test is not used for routine therapeutic drug level monitoring. Use only to evaluate severity of intoxications.

Literature References:

Package insert: Acetaminophen. Roche Diagnostics, 2010.

Specimen Requirements

Specimen Type: Plasma
Container/Tube: 1 mint green-top (lithium or sodium heparin) tube
Specimen Volume: Full tube


Day(s) Test Set Up

Monday through Sunday

Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: results available the day of testing

Reference Values

Therapeutic range: 10-20 mcg/mL

Critical value (automatic call-back): ≥50 mcg/mL.


Significant hepatic injury may occur and treatment with N-acetyl cysteine is generally recommended if the acetaminophen level exceeds:
150 mcg/mL at 4 hours after ingestion
75 mcg/mL at 8 hours after ingestion
38 mcg/mL at 12 hours after ingestion
19 mcg/mL at 16 hours after ingestion

Literature Reference:

Waldman SA, Terzic A. Pharmacology and therapeutics, principles to practice. Saunders Elsevier, Philadelphia, PA: 2009.

Test Classification and CPT Coding



Additional Information

For BJH Laboratory Use Only

Alternate Tube:

1 blue-top (citrate) tube

1 dark green-top (lithium or sodium heparin) tube
1 grey-top (potassium oxalate/sodium fluoride) tube
1 lavender-top (EDTA) tube

1 plain red top tube
Separator gel tube is acceptable

Analyte Stability:

Unprocessed specimen may be stored ambient or refrigerated (2° C to 8° C) up to 24 hours. Processed specimen may be stored ambient or refrigerated (2° C to 8° C) up to 2 weeks. Freeze specimen for longer storage and avoid repeated freeze-thaw cycles.

Laboratory Processing Instructions:
Test performed in BJH Chemistry. Centrifuge upon receipt. Deliver to the Modular station. Completed specimen is stored refrigerated for 1 week.

Specimen Transport Temperature


LOINC Code Information

Name LOINC Code
Acetaminophen, Plasma 3298-7