This information is for educational purposes only. Off-label drug use carries risks. Always consult a qualified physician before using any drug outside its approved indication.
Dipyridamole
Dipyridamole
Brand names: Persantine, Aggrenox (with aspirin)
ORIGINALLY APPROVED FOR
Prevention of Blood Clots, Strokes, Cardiac Imaging
Dipyridamole inhibits phosphodiesterases and blocks adenosine uptake, elevating extracellular adenosine — which activates A2A receptors on immune cells and creates an immunosuppressive environment that can actually cut both ways in cancer. More interestingly, dipyridamole inhibits thymidylate synthase — the same target as 5-fluorouracil — making it a natural chemosensitiser to 5-FU based regimens. Clinical studies in colorectal and gastric cancer have shown improved outcomes when combined with chemotherapy.
Molecular Pathways Targeted
Mechanism of Action in Cancer
Inhibits thymidylate synthase → depletes thymidine for DNA synthesis → synergises with 5-FU and other antimetabolites. Blocks adenosine deaminase → elevates adenosine → modulates tumour microenvironment. Raises cAMP/cGMP via PDE inhibition → reduces cancer cell migration and platelet-mediated tumour support.
Cancers Studied
Typical Off-Label Dosing
75–150 mg three times daily (standard cardiovascular dosing). Cancer combination studies have used 75–200 mg three times daily. Often studied with 5-FU based chemotherapy regimens.
* Dosing information from research literature only. Not a prescription. Requires physician supervision.
Cautions & Drug Interactions
- Significant vasodilatory effects — avoid in severe hypotension or unstable angina
- Headache, flushing, GI upset are common — especially when starting
- Potentiates adenosine — avoid with theophylline (antagonist) or in myasthenia gravis
- Increased bleeding risk when combined with aspirin or anticoagulants
- Avoid in bleeding disorders
- Evidence for cancer is relatively preliminary — mainly used as chemotherapy adjunct