Lab Test

Caffeine Level

Test Codes

Antrim #31439, EPIC: LAB5890, SOFT: CAFFE



Specimen Collection Criteria

Collect: One plain Red-top tube. (Minimum Whole Blood: 1.0 mL)

Do not use Serum Separator Tubes.

Record the exact time of specimen collection on the tube or in the computer system.
See Minimum Pediatric Specimen Requirements for Microtainer® collection.

Physician Office/Draw Specimen Preparation

Let specimens clot 30-60 minutes. Refrigerate (2-8°C or 36-46°F) the collection tube within two hours of collection. (Minimum: 2.0 mL blood)

Preparation for Courier Transport

Transport: Collection tube, refrigerated (2-8°C or 36-46°F). (Minimum: 1.0 mL blood)

Rejection Criteria

  • Serum Separator (SST) tubes.
  • Severely lipemic or hemolyzed specimens. 

In-Lab Processing

Let specimens clot 30-60 minutes. Centrifuge specimen to separate serum from cells. Deliver an aliquot of serum or the collection tube immediately to the appropriate testing station.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 3 months

Specimen Storage in Department Prior to Disposal:

Frozen (-20°C/-4°F or below): 1 month


Royal Oak Toxicology Laboratory


Saturday – Sunday, 24 hours a day.
STAT results available within 2 hours of receipt in the Laboratory.
Routine results available within 24 hours.

Reference Range

Therapeutic Range: 10-20 mcg/mL.
Critical Range: Greater than 30 mcg/mL.

Test Methodology

Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS).

This test was developed and its performance characteristics determined by Beaumont Health. It has not been cleared or approved by the FDA. The Laboratory is regulated under CLIA as qualified to perform high-complexity testing. This test is used for clinical purposes and should not be regarded as investigational or for research.


Caffeine is a stimulant and a bronchodilator. It is contained in coffee, tea, cocoa and many soft drinks.

Half Life in Blood: 20 – 100 hours in neonates.

Clinical Utility

This assay is used to monitor the therapeutic drug level and evaluate the toxicity of caffeine. Caffeine is used in the treatment of apnea that occurs in newborn infants. Apnea in the newborn is the most frequent complication seen in the neonatal nursery. Caffeine toxicity in neonates is characterized by central nervous system and skeletal muscle stimulation and bradycardia.

CPT Codes

LOINC: 3422-3


Last Updated


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