Pharmaceutical compositions containing a stilbene such as resveratrol, a flavonol such as quercetin, and a TLR4/MD2 receptor antagonist such as naltrexone or curcumin inhibit aggregation of superactivated platelets, block activation of the coagulation cascade, and are useful for treating microvascular diseases including neurodegenerative diseases such as Alzheimer's disease and dementia, for treating primary open-angle glaucoma, for reducing scar formation, and like afflictions that involve the coagulation cascade.