Butyrylcholinesterase (BChE) activity in serum/plasma

This test measures the activity of butyrylcholinesterase (BChE), an enzyme made mainly by the liver. BChE helps your body break down certain drugs, including some anesthetics and pesticides, so measuring its activity shows how well your body can process these substances.

Butyrylcholinesterase (BChE) is an enzyme found in your blood that plays a role in metabolizing certain drugs, including some anesthetics, nerve agents, and certain medications used to treat conditions like Alzheimer’s disease. Your body naturally produces this enzyme, and its activity can vary based on genetics, medications, and health conditions.

Your doctor may order this test if you or a close relative had prolonged muscle paralysis, weakness, or breathing difficulty after receiving anesthesia drugs such as succinylcholine or mivacurium. It may also be used to check for possible exposure to certain insecticides or to help evaluate liver health.

Doctors may order this test if you’re taking medications that rely on BChE for metabolism, such as some nerve agents (e.g., sarin) or certain anesthetics. It can also be used in research or clinical settings to monitor exposure to toxins or to evaluate genetic variations that affect enzyme function.

In healthcare, BChE testing is commonly used to investigate unexpected sensitivity to anesthesia, screen family members for an inherited enzyme deficiency, monitor workers exposed to organophosphate pesticides, and support the evaluation of liver disease or other conditions affecting enzyme production.

This test is less commonly performed in routine clinical settings but may be used in specialized scenarios, such as toxicology evaluations, drug monitoring, or research studies involving enzyme activity.

Before the test, tell your provider about all medications, supplements, and possible pesticide exposure, since many substances can temporarily lower BChE activity. The test is a routine blood draw, and fasting is usually not required unless your provider gives you specific instructions. Follow any guidance about pausing certain medicines.

No special preparation is typically required, but you may be asked to fast for a few hours before your blood is drawn. Follow your healthcare provider’s instructions if you’re taking medications that could affect enzyme levels.