What are the other Names for this Test? (Equivalent Terms)

• Paracetamol Blood Test 

What is Acetaminophen Blood Test? (Background Information)

• Acetaminophen is available over the counter as one of the most commonly used medication for pain relief (analgesic) and fever (antipyretics). It is also known as paracetamol
• The liver is primarily involved in processing this medication. However, if the medication is taken in excess of its recommended dosage, it may cause damage of the liver cells
• Without an early treatment of this damage, it may lead to liver failure. Liver damage occurs due to the accumulation of a toxic intermediate metabolite of acetaminophen in blood
• The Acetaminophen Blood Test helps in assessing the level of the acetaminophen drug in blood. This aids in diagnosing an overdose and the risk of liver damage. It also helps in making a decision regarding the treatment to be provided 

What are the Clinical Indications for performing the Acetaminophen Blood Test?

Following are the clinical indications for performing an Acetaminophen Blood Test:

• If there is a suspicion of acetaminophen overdose, blood is drawn and sent to check for acetaminophen levels, every 4 to 6 hours after ingestion
• If the sample is drawn early, the results may not correlate with the amount of drug ingested and absorbed

Some of the symptoms of acetaminophen overdose include:

• Nausea, vomiting, and diarrhea
• Sweating
• Abdominal pain or cramping
• Loss of appetite
• Unusual bleeding or bruising
• Flu-like symptoms
• Yellowing of the skin or eyes 

How is the Specimen Collected for Acetaminophen Blood Test?

Following is the specimen collection process for Acetaminophen Blood Test:

Sample required: Blood             

Process: Insertion of a needle into an arm vein.

Preparation required: No special preparation is needed prior to the test. 

What is the Significance of the Acetaminophen Blood Test Result?

The reference range for acetaminophen may vary slightly from lab to lab. Hence, most lab reports come with a reference range, which is used in that particular centre. A physician interprets the results based on the reference values provided. 

Generally, the result is interpreted as follows for acute toxicity:

• Normal levels: 10-30 mcg/ml
• Low risk of liver damage: Levels less than 150 mcg/ml, 4 hours after ingestion
• Serious liver damage: Levels more than 200 mcg/ml, 4 hours after ingestion; or more than 50 mcg/ml, 12 hours after ingestion

The Acetaminophen Blood Test result is also interpreted considering the following factors:

• Age
• Gender
• Medical history of the patient
• The laboratory testing method used

Additional and Relevant Useful Information:

• Acetaminophen is available as a prescription and non-prescription drug in combination with other medications. It is also sold over-the-counter under various brand names for pain and fever
• The risk of liver damage, increases in patients consuming acetaminophen with alcohol, or those having liver problems
• It is advisable to always consult your physician prior to taking acetaminophen; especially, if you have any liver conditions that puts you at risk for liver damage