LACunar Intervention (LACI-2) Trial-2

Inclusion Criteria: * Clinical lacunar stroke syndrome. * Brain scanning\* with MR including diffusion imaging wherever possible, and obtained soon after the presentation with stroke, shows either: * a recent, relevant (in time and location) acute lacunar infarct on diffusion MR imaging1, * or, if no visible acute lacunar infarct on diffusion MR imaging2 then there is no competing pathology as a cause for stroke (e.g. no acute cortical infarct, no acute intra-cerebral haemorrhage, no stroke mimic such as tumour, subdural haematoma); * or, if only a CT brain scan is available2 as in section 3 above, then there is a small relevant (in age and location) subcortical infarct, or if no infarct then there is no competing pathology as a cause for stroke (e.g. no acute cortical infarct, no acute intra-cerebral haemorrhage, no stroke mimic such as tumour, subdural haematoma). 1. Note that if there is no acute lacunar infarct on MR diffusion imaging but there is a recent-appearing lacunar infarct on FLAIR, T2, or T1 (i.e. no cavitation or ex-vacuo effect; may be slightly swollen, ill-defined edges; or scan in the few weeks before the stroke does not show a lesion but there is an acute lacunar infarct on MR T2, FLAIR, T1 scanning after the stroke in an appropriate area of the brain for symptoms), then the T2, FLAIR, T1 lesion may be counted as the acute lacunar infarct in the absence of a diffusion lesion. Similarly, on CT2 a recent relevant small subcortical infarct would not show cavitation or shrinkage/ex vacuo effect. 2. Note that about a third of patients with a clinically definite lacunar syndrome do not have a corresponding recent infarct visible on MRI but should still be classed as 'lacunar stroke' if no other explanation can be found for the symptoms. The presence of a recent cortical infarct on FLAIR, T2, T1, the recent timing being indicated by the characteristics above, would count as a competing pathology. Note that the complete absence of any abnormality on MR or CT brain imaging (no acute subcortical infarct or pre-existing SVD such as white matter hyperintensities, lacunes, etc.) while occasionally seen in lacunar stroke is unusual and should question the diagnosis of lacunar ischaemic stroke. * Age \> 30 years * Independent in activities of daily living (modified Rankin ≤2) * Capacity to give consent themselves Exclusion Criteria: * Other significant active neurological illness present since suffering stroke (e.g. recurrent seizures, multiple sclerosis, brain tumour). Well-controlled epilepsy present prior to the stroke, a single seizure at onset of the stroke or provoked seizure is not an exclusion. * Requiring assistance with activities of daily living (Modified Rankin ≥3) * Has been diagnosed as having dementia on formal clinical assessment * Active cardiac disease (atrial fibrillation, myocardial infarction in past 6 months, active angina, symptomatic cardiac failure) * Diagnosis of hypotension, defined as sitting systolic blood pressure less than 100mmHg * Definite indication for (i.e. already prescribed) either trial medication, or definite contraindication to a trial drug as per SPCs - lactose intolerance is a contraindication to ISMN preparations which contain lactose monohydrate - (indication for or contraindication to one of the trial drugs still allows randomisation to the other trial drug) * Unable to swallow tablets * Bleeding tendency (e.g. known platelets\<100, active peptic ulcer, history of intracranial haemorrhage such as subdural haematoma, subarachnoid haemorrhage, intracerebral haemorrhage, but not asymptomatic haemorrhagic transformation of infarction or a few microbleeds, taking anticoagulant medication) * Planned surgery during the trial period including carotid endarterectomy. Note prior and apparently successful carotid endarterectomy (or other surgery) is not an exclusion criterion and patients who would otherwise be eligible but require endarterectomy first may be randomised after recovery from successful endarterectomy. * Other concurrent life threatening illness * Unlikely to be available for follow-up (e.g. moving outside or visitor to the area) * History of drug overdose or attempted suicide or significant active mental illness * Pregnant or breastfeeding women, women of childbearing age not taking contraception. Acceptable contraception in women of childbearing age is a "highly effective" contraceptive measure as defined by the Clinical Trials Facilitation Group (http://www.hma.eu/fileadmin/dateien/Human\_Medicines/01-About\_HMA/Working\_Groups/CTFG/2014\_09\_HMA\_CTFG\_Contraception.pdf) and includes combined (oestrogen and progesterone containing) or progesterone-only contraception associated with inhibition of ovulation, or intrauterine device or bilateral tubal occlusion. Contraception must be continued for up to 30 days after the end of the IMP dosing schedule. * Prohibited medications to either trial drug (see sections 4.5 of the appended SPCs and protocol section 6.6.3, plus no anticoagulant drugs); (prohibited medications to one of the trial drugs still allows randomisation to the other trial drug). * Renal impairment (creatinine clearance \<25 ml/min) * Hepatic impairment * Current enrolment in another Clinical Trial of Investigational Medicinal Product (CTIMP); still in extended follow-up beyond the CTIMP primary outcome and no longer taking that trial's IMP is not an exclusion to enrolment in LACI-2. * Unable to tolerate MRI or contraindication to MRI (Claustrophobia, Pacemaker)