Could a 4p blood pressure pill treat dementia?
Thursday, 5th December, 2013
A drug that's widely prescribed for high blood pressure could become the first ever treatment for a common type of dementia.
Amlodipine, which costs just 4p a day, is to be tested on people with vascular dementia in a £2.25 million clinical trial.
Vascular dementia affects around 150,000 people in the UK and is the second most common form of dementia after Alzheimer's.
It is caused by reduced blood supply to the brain (either temporary or long-term) because of damage to blood vessels. It can also be triggered by a stroke.
High blood pressure is a major risk factor, as is having high cholesterol, diabetes or a heart condition.
There are no licensed treatments for vascular dementia, and fewer on-going clinical trials for it than for hay fever.
Amlodipine is already used for treating patients with high blood pressure. It's a form of calcium channel blocker, and blocks the action of calcium (which narrows blood vessels), helping relax blood vessels and lowering blood pressure.
Blood pressure drugs are already thought to help lower the risk of developing dementia, including Alzheimer's. But amlodipine is the first to be properly tested as a treatment for dementia.
In a major two-year trial, researchers at the School of Medicine, Dentistry and Biomedical Sciences at Queen's University, Belfast, are going to test if amlodipine can prevent the disease progressing, and improve memory and cognition (previous smaller-scale studies have suggested it might).
One theory is that reducing blood pressure helps improve blood flow to the brain.
The drug's effect on calcium in the brain may also help, as calcium is also thought to have a role in the death of brain cells, says lead investigator Professor Peter Passmore.
Nearly 600 people will take part in the study, with half given a dummy pill. Participants will have their brains scanned at the beginning of the trial and a year later.
They will also have their memory tested regularly. If successful, it could see amlodipine being used as a treatment for vascular dementia within five to ten years.
Jeremy Hughes, chief executive of the Alzheimer's Society, which is funding the trial with the British Heart Foundation, says it is 'scandalous' that 'despite affecting 150,000 people there are no effective treatments for vascular dementia and very few under investigation'.
He adds: 'Developing new drugs from scratch can cost hundreds of millions and take up to 20 years, but our drug discovery programme aims to test existing drugs licensed for other uses, fast-tracking the process and bringing new treatments to market faster and more cheaply.'
Rob Howard, professor of old age psychiatry at King's College London's Institute of Psychiatry, says the study is 'certainly interesting', adding: 'For many years we have told our patients when they have asked us how to avoid dementia, that what is good for the heart (such as treating high blood pressure) is likely to be good for the brain.
Participants will have their brains scanned at the beginning of the trial and a year later
'A properly conducted large-scale clinical trial is the only way to really investigate once and for all whether or not this is true. This is timely and worthwhile.'
He adds that his only concern is that it may reduce blood pressure in people who do not need it.
To find out about taking part, visit alzheimers.org.uk/vasculartrial or bhf.org.uk/dementia.
Meanwhile, scientists from Cambridge University have suggested that Alzheimer's may be linked to head injuries.
They studied a protein called tau, normally found in healthy cells. Clumps of tau have been found in brains of people who died from the disease, and are thought to play a part in stopping brain cells (neurons) working.
When the scientists added small amounts of tau to the outside of neuron-like cells, the cells started ingesting the protein. This in turn triggered the tau to form clumps.
Writing in the Journal of Biological Chemistry, the scientists said that anything which causes tau to escape from inside cells may trigger Alzheimer's. Head injuries are a main candidate for this, along with brain tumours and Parkinson's disease.
Source Mail Online