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. Check for active clinical trials using this agent. (NCI Thesaurus)