Dipyridamole, a non-nitrate coronary vasodilator that also inhibits platelet aggregation, is combined with other anticoagulant drugs, such as warfarin, to prevent thrombosis in patients with valvular or vascular disorders. Dipyridamole is also used in myocardial perfusion imaging, as an antiplatelet agent, and in combination with aspirin for stroke prophylaxis. Dipyridamole likely inhibits both adenosine deaminase and phosphodiesterase, preventing the degradation of cAMP, an inhibitor of platelet function. This elevation in cAMP blocks the release of arachidonic acid from membrane phospholipids and reduces thromboxane A2 activity. Dipyridamole also directly stimulates the release of prostacyclin, which induces adenylate cyclase activity, thereby raising the intraplatelet concentration of cAMP and further inhibiting platelet aggregation. Used for as an adjunct to coumarin anticoagulants in the prevention of postoperative thromboembolic complications of cardiac valve replacement and also used in prevention of angina.

Fluorocyclopentenylcytosine (RX-3117) is a novel small molecule nucleoside compound that is incorporated into DNA or RNA of cancer cells and inhibits both DNA and RNA synthesis which induces apoptotic cell death of tumor cells. Fluorocyclopentenylcytosine also mediates the down-regulation of DNA methyltransferase 1 (DNMT1), an enzyme responsible for the methylation of cytosine residues on newly synthesized DNA and also a target for anticancer therapies. Preclinical studies have shown Fluorocyclopentenylcytosine to be effective in both inhibiting the growth of various human cancer xenograft models, including colon, lung, renal and pancreas, as well as overcoming chemotherapeutic drug resistance. Fluorocyclopentenylcytosine has demonstrated a broad spectrum anti-tumor activity against 50 different human cancer cell lines and efficacy in 12 different mouse xenograft models. The efficacy in the mouse xenograft models was superior to that of gemcitabine. In addition, in human cancer cell lines made resistant to the anti-tumor effects of gemcitabine, Fluorocyclopentenylcytosine still retains its full anti-tumor activity. In August 2012, Rexahn reported the completion of an exploratory Phase I clinical trial of Fluorocyclopentenylcytosine in cancer patients conducted in Europe, to investigate the oral bioavailability, safety and tolerability of the compound. In this study, oral administration of Fluorocyclopentenylcytosine demonstrated an oral bioavailability of 34-58% and a plasma half-life (T1/2) of 14 hours. In addition, Fluorocyclopentenylcytosine was safe and well tolerated in all subjects throughout the dose range tested. Fluorocyclopentenylcytosine is in phase I/II clinical trials by Rexahn for the treatment of bladder cancer and pancreatic cancer. This compound was granted Orphan Drug Designation by the U.S. Food and Drug Administration (FDA) for the treatment of patients with pancreatic cancer in September 2014.