Allopurinol is a type of drug called a ‘xanithine oxidase inhibitor’. Allopurinol is used to prevent gout, a condition where salt crystals build up within a joint causing pain and swelling.
Allopurinol has also shown promise as a drug to reduce stroke risk. It has been shown to reduce a number of cardiovascular risk factors which can lead to stroke. These risk factors are also indicators of scars building up on the brain called ‘white matter hyper-intensities’ (WHM). Such WHM appear around the site of a stroke in about 90% of all strokes where blood clots block blood flow to the brain (ischaemic stroke). Critically, WHM are predictive of future stroke, dementia, and cognitive decline.
In the current study, 464 stroke survivors will take part for two years. Over this time, half of them will receive 300mg of allopurinol twice daily, and the other half will receive an equivalent ‘dummy’ drug.
At the beginning and end of the study, all participants will have a brain scan to compare changes in levels of WHM brain scarring between the allopurinol and the dummy-drug groups. Eligible participants will also form sub-groups to additionally test for heart muscle thickness and blood pressure – both stroke risk factors.
If the study finds that allopurinol has a beneficial effect to stroke survivors, it would promptly be followed up by a larger, worldwide study to confirm the benefit.