Tadalafil – Cialis’ active ingredient – belongs to the same class of medications (PDE5 inhibitors) as Pfizer’s Viagra, and works by dilating blood vessels in the penis so blood can flow there more easily.
Because of its benefits to blood flow, scientists were curious if tadalafil could help to avert the development of a common form of dementia (vascular dementia) by again increasing blood flow, but this time to the brain.
The Alzheimer’s Society and the Alzheimer’s Drug Discovery Foundation (ADDF) in New York are jointly funding the £328,000 cross-Atlantic research partnership.
Scientists led by Dr Atticus Hainsworth at St George’s, University of London, will assess 50 people aged over 65 in the UK that have experienced mild symptoms of dementia – such as memory loss – or have shown signs of blood vessel damage, following a stroke.
Dr Hainsworth commented: “My colleagues and I are very enthusiastic about this trans-Atlantic initiative as there are too few drugs in the medicine cupboard for dementia. We want to know whether a well-known, well-tolerated drug can be used to combat dementia, which has been called the twenty first century plague. The drug Tadalafil is widely used to increase blood flow in penile tissue. Now we’re asking whether it can do the same for another vital organ – the brain.”
Vascular dementia is the second most common type of dementia and an estimated 110,000 cases of dementia in the UK are this form of the disease. It is usually caused due to damage of the small blood vessels of the brain, leading to less blood being transported to the brain tissue as the artery walls are too thick and stiff.
This type of damage is also referred to as ‘small vessel disease’ and is evident in around 50-70% of older people because the damage usually develops and worsens over many years.
However, the researchers involved in the new clinical trials are optimistic that tadalafil’s blood-flow boosting properties will hopefully be able to stop the damage that causes vascular dementia.
The researchers will monitor the participants’ blood flow to the brain prior to and following a dose of tadalafil, using a special type of MRI called arterial spin labelling.
This involves the use of radiowaves to magnetise water within the blood and then monitor it as it travels to the brain, which will help the researchers to see the amount of blood that is getting to different areas of brain tissue.
The low dose of tadalafil will occasionally be switched for a placebo so the scientists can contrast the blood flow with and without tadalafil.
Patients already with dementia will be unable to be involved in the trials as those pioneering the research say they want to see if tadalafil may be able to actually prevent the onset of the disease.
Dr Doug Brown, Director of Research and Development at Alzheimer’s Society, said: “Drug development can take decades and sadly, the path towards developing dementia treatments over the past decade is littered with drugs that have failed in clinical trials. As we learn more about the causes of dementia and its links to other conditions, there is hope that treatments we routinely use for other diseases may also work for people with dementia.
“These incredibly exciting studies could see existing treatments turned into drugs for the most common forms of dementia in a fraction of the time and at a fraction of the cost of developing new drugs from scratch. By next year 850,000 people in the UK will have dementia and we owe it to them to do everything we can to develop better treatments and ultimately find a cure. Research like this is a huge part of that goal.”
