title: Drugs licensed for treating patients with alzheimer's disease.
abstract: Four drugs are licensed in the UK for the management of Alzheimer's disease. These are the cholinesterase inhibitors donepezil, rivastigmine and galantamine, and memantine, which decreases the action of the neurotransmitter glutamate. Cholinesterase inhibitors increase the availability of acetylcholine at the synaptic cleft between neurones by preventing its breakdown by the enzyme acetylcholinesterase. The four drugs are only licensed for Alzheimer's disease, with rivastigmine also licensed for Parkinson's disease. For vascular dementia they have been shown to give modest improvements in cognitive function but not for activities of living and so are not recommended.