Acetaminophen
Also known as: Acephen™, APAP 500, Aspirin Free Anacin® Extra Strength, Cetafen®, Excedrin® Tension Headache
Use
Monitor therapeutic drug levels; evaluate for acetaminophen toxicity. Acetaminophen is as effective as aspirin when used for analgesia and antipyresis. It is used to treat headache, mild-to-moderate myalgia, arthralgia, chronic pain of cancer, postpartum pain, postoperative pain, and fever. The ceiling analgesic effect is obtained with a dose of 1 g.
Special Instructions
The use of gel-barrier tubes is not recommended due to slow absorption of the drug by the gel, which can affect test accuracy. For toxicity evaluation, draw a sample 4 to 6 hours after ingestion and a second sample 3 to 4 hours later to properly assess acetaminophen levels.
Limitations
Acetaminophen does not possess potent anti-inflammatory properties like aspirin, making it unsatisfactory for conditions such as rheumatic disease or juvenile arthritis. It does not interfere with uricosuric agents and may be used in patients with gout. Hepatic toxicity may occur due to reactive liver metabolites, highlighting the importance of monitoring liver function after suspected overdose.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 3298-7
- 3298-7
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2 mL
Minimum Volume
0.6 mL
Container
Red-top tube or green-top (heparin) tube. Do not use a gel-barrier tube.
Collection Instructions
Transfer separated serum or plasma to a plastic transport tube. For toxicity assessment, draw a sample 4 to 6 hours after ingestion and a second sample 3 to 4 hours later.
Storage Instructions
Room temperature
Causes for Rejection
Gel-barrier tube; hemolysis; gross lipemia; icteric specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |