Acetylcholinesterase (AChE) is a serine hydrolase whose primary function is to hydrolyze the neurotransmitter acetylcholine (ACh), breaking it down into acetic acid and choline. This terminates the signal that acetylcholine generates, hindering further communication between the neuron and muscle cell, leading to the relaxation of a muscle fiber.  

There are two classes of AChE inhibitors: 

• Reversible inhibitors, which have a temporary and reversible effect on the enzyme’s activity and are typically used in therapeutic applications
• Irreversible inhibitors, which have a longer-lasting effect on the enzyme’s activity and are more commonly associated with toxic effects