People with Alzheimer’s disease experience a loss of nerve cells that use a chemical called acetylcholine as a chemical messenger. Dementia symptoms become more severe as more nerve cells are lost.
Cholinesterase inhibitors are a group of drugs (including donepezil, rivastigmine and galantamine) that prevent the enzyme acetylcholinesterase from breaking down acetylcholine in the brain. All three drugs work in a similar way, but they have quite different side-effect profiles in different people.
At present, rivastigmine is the only cholinesterase inhibitor licensed for treating mild to moderate dementia in Alzheimer’s disease and Parkinson’s disease in the UK. Donepezil and galantamine are only licensed in mild to moderate Alzheimer’s disease.
A new Cochrane systematic review has recently been published that seeks to assess the efficacy, safety and tolerability of cholinesterase inhibitors in three different conditions:
- Dementia with Lewy bodies
- Parkinson’s disease with dementia
- Cognitive impairment in Parkinson’s disease falling short of dementia
The reviewers conducted a systematic search but only found 6 trials to included in their reviewer, involving total of 1,236 patients:
- 1 trial included patients with dementia with Lewy bodies
- 4 trials included participants with a diagnosis of Parkinson’s disease with dementia
- 1 trial included patients with cognitive impairment and Parkinson’s disease (both with and without dementia)
Here’s what they found:
- Cholinesterase inhibitors had a positive impact on global assessment, cognitive function, behavioural disturbance and activities of daily living in patients with Parkinson’s disease with dementia
- The effect of cholinesterase inhibitors remains unclear in patients with Dementia with Lewy bodies
- They found no evidence to support the use of cholinesterase inhibitors in patients with cognitive impairment in Parkinson’s disease falling short of dementia
Rolinski M, Fox C, Maidment I, McShane R. Cholinesterase inhibitors for dementia with Lewy bodies, Parkinson’s disease dementia and cognitive impairment in Parkinson’s disease. Cochrane Database of Systematic Reviews 2012, Issue 3. Art. No.: CD006504. DOI: 10.1002/14651858.CD006504.pub2.