Using Viagra’s active ingredient to expose the migraine

The substance sildenafil – the primary component in Viagra – is commonly administered to treat erectile dysfunction.

However sildenafil also happens to have other creative applications, and the substance is now being used in an experiment involving migraines. The experiment, which is funded by the Lundbeck Foundation, is being carried out at the Danish Headache Center based at Rigshospitalet – Glostrup. The test subjects are volunteers – both women and men – who suffer from migraines and are willing to ingest sildenafil and another substance, calcitonin gene-related peptide (CGRP), and then have their brains scanned. CGRP is a little protein that is found naturally in the body. It is involved in the transmission of signals between nerve cells, and both sildenafil and CGRP can trigger migraines. Scientists have been aware of this connection for many years. At the Danish Headache Center, the hope is to learn more about the tiny blood vessels found around the membranes of the human brain, explains Dr Casper Emil Christensen, PhD fellow:

“The hypothesis is that these tiny blood vessels can play a central role in connection with the development of a migraine. And we’re currently investigating how this part of human biology works in more detail with the help of sildenafil and CGRP.’

Scanning the brain
Prior to this project, Casper Emil Christensen, in collaboration with Danish and Dutch colleagues, conducted a preliminary study to investigate the effect of the two substances on test subjects who do not suffer from migraines: After healthy test subjects were given the substances – sildenafil on one day and CGRP on another – they were scanned with the help of, among others, the powerful 7 Tesla MR scanner at Hvidovre Hospital. The results of these scans were recently published in the scientific journal The Journal of Headache and Pain, and they revealed something very interesting according to Casper Emil Christensen:

‘In the scans, we could see how both sildenafil and CGRP caused the tiny blood vessels around the brain membrane to expand. Now we’re repeating the experiment – only on people who actually suffer from migraines. The hope is that the scans will reveal reactions that are specific to this patient group. If we’re lucky, in the form of a biological “fingerprint” for migraines.’

And there is serious need for this ‘fingerprint’:

‘The fact is that as doctors we aren’t always sure whether a patient has migraines clinically speaking – or whether the pain he or she is experiencing is actually some other type of headache.’

A ‘fingerprint’ would also be helpful in connection with the development of new courses of treatment for migraines, including new drugs,’ explains Casper Emil Christensen:

‘But we won’t know whether we have identified a ‘fingerprint’ until the many brain scans have been analysed. And that will take us some time.’