Dipyridamole
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Dipyridamole
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Systematic (IUPAC) name | |
2-{[9-(bis(2-hydroxyethyl)amino)-2,7-bis(1-piperidyl)- 3,5,8,10-tetrazabicyclo[4.4.0]deca-2,4,7,9,11-pentaen- 4-yl]-(2-hydroxyethyl)amino}ethanol |
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Identifiers | |
CAS number | |
ATC code | B01 |
PubChem | |
DrugBank | |
Chemical data | |
Formula | C24H40N8O4 |
Mol. mass | 504.626 g/mol |
Pharmacokinetic data | |
Bioavailability | ? |
Protein binding | 99% |
Metabolism | ? |
Half life | 40 minutes |
Excretion | ? |
Therapeutic considerations | |
Pregnancy cat. |
B |
Legal status | |
Routes | PO, IV |
Dipyridamole is a drug that inhibits platelet aggregation and causes vasodilation.
- It inhibits the cellular reuptake of adenosine into platelets, red blood cells and endothelial cells leading to increased extracellular concentrations of adenosine.
- It also inhibits the enzyme adenosine deaminase which normally breaks down adenosine into inosine. This inhibition leads to further increased levels of extracellular adenosine.
- Dipyridamole also inhibits the enzyme phosphodiesterase which normally breaks down cAMP.
- Adenosine interacts with the adenosine receptors to cause increased cAMP via adenylate cyclase.
- cAMP impairs platelet aggregation and also causes arteriolar smooth muscle relaxation.
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[edit] Use in individuals with a history of stroke
Modified release dipyridamole is used in conjunction with aspirin (under the trade name Aggrenox®) in the secondary prevention of stroke and transient ischemic attack.[1] This practice is now confirmed by the ESPRIT trial.
[edit] Use in nuclear stress testing
Dipyridamole (Persantine) is also used in nuclear cardiac stress testing as a coronary vasodilator.
- Via the mechanisms mentioned above, it increases the local concentration of adenosine in the coronary circulation which causes vasodilation.
- Vasodilation occurs in healthy arteries, whereas stenosed arteries remain narrowed. This creates a "steal" phenomena where the coronary blood supply will increase to the dilated healthy vessels at the expense of the stenosed arteries which can then be detected by clinical symptoms of chest pain, electrocardiogram and echocardiography when it causes ischemia.
- Flow heterogeneity (a necessary precursor to ischemia) can de detected with gamma-cameras and SPECT using nuclear imaging agents such as Thallium-201 and Tc99m-Sestamibi.
[edit] Other uses of dipyridamole
Dipyridamole also has non-medicinal uses in a laboratory context, such as the inhibition of cardiovirus growth in cell culture.
[edit] References
- ^ Diener HC, Cunha L, Forbes C, Sivenius J, Smets P, Lowenthal A. (1996). "European Stroke Prevention Study 2. Dipyridamole and acetylsalicylic acid in the secondary prevention of stroke.". J Neurol Sci 143 (1-2): 1-13. PMID 8981292.
- Dipyridamole in the laboratory: Fata-Hartley, Cori L.; Ann C. Palmenberg. Dipyridamole reversibly inhibits mengovirus RNA replication. Retrieved on February 13, 2007..