ChEBI: Dipyridamole is a pyrimidopyrimidine that is 2,2',2'',2'''-(pyrimido[5,4-d]pyrimidine-2,6-diyldinitrilo)tetraethanol substituted by piperidin-1-yl groups at positions 4 and 8 respectively. A vasodilator agent, it inhibits the formation of blood clots. It has a role as an adenosine phosphodiesterase inhibitor, an EC 3.5.4.4 (adenosine deaminase) inhibitor, a platelet aggregation inhibitor and a vasodilator agent. It is a member of piperidines, a pyrimidopyrimidine, a tertiary amino compound and a tetrol.NCI Thesaurus (NCIt): Dipyridamole is a synthetic agent derivative of pyrimido-pyrimidine, with antiplatelet properties. Dipyridamole inhibits adenosine uptake by platelets and endothelial cells, triggering an accumulation of cyclic adenosine monophosphate (cAMP), and inhibiting the stimulation of platelet aggregation by agents such as platelet activating factor and collagen. (NCI04)