Cholinesterase inhibitors

Cholinesterase inhibitors (also called acetylcholinesterase inhibitors) are a group of medicines that block the normal breakdown of acetylcholine. Acetylcholine is the main neurotransmitter found in the body and has functions in both the peripheral nervous system and the central nervous system. For example, acetylcholine is released by motor neurons to activate muscles; acetylcholine also has an important role in arousal, attention, learning, memory and motivation.

Cholinesterase inhibitors block the action of the enzyme cholinesterase, which is responsible for breaking down acetylcholine. This increases levels of acetylcholine in the synaptic cleft (the space between two nerve endings).

The main use of cholinesterase inhibitors is for the treatment of dementia in patients with Alzheimer's disease. People with Alzheimer's disease have reduced levels of acetylcholine in the brain. Cholinesterase inhibitors have been shown to have a modest effect on dementia symptoms such as cognition.

Cholinesterase inhibitors tend to cause side effects such as vasodilation, constriction of the pupils in the eyes, increased secretion of sweat, saliva and tears, slow heart rate, mucus secretion in the respiratory tract and constriction of the airways.