Table 1.

Full inclusion and exclusion criteria.

Inclusion criteria	Exclusion criteria
Ischaemic stroke/ischaemic lesion on brain imaging in relevant anatomical territory in patients with transient ischaemic attack	Modified Rankin scale score of 5
Age greater than 50	Diagnosis of dementia
Consent within one month of stroke	Cognitive impairment deemed sufficient to compromise capacity or comply with the protocol
	Dependent on daily help from others for basic activities prior to stroke
	Significant co-morbidity or frailty likely to cause death within 24 months
	Contra-indication to or indication for administration of allopurinol
	Concurrent azathioprine, 6-mercaptopurine therapy, other cytotoxic therapies, cyclosporin, theophylline and didanosine
	Significant hepatic impairment
	eGFR < 30 ml/min
	Contraindication to MRI scanning
	Women of childbearing potential
	Prisoners
	Active participation in another CTIMP or device trial or participation within the past month
	eGFR < 60 and of Korean, Han Chinese or Thai descent

MRI: magnetic resonance imaging; eGFR: estimated glomerular filtration rate; CTIMP: Clinical trial of investigational medicinal product.