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Vasodilators: Amyl Nitrite, Nitroglycerin

Vasodilators: Amyl Nitrite, Nitroglycerin

Vasodilators

Dr. GlGopal KihKrishna PdhPadhy Assoc. Professor CtiCenturion UiUnivers ity of ThlTechnology an d Management Introduction Vasodilators are a group of medicines that dilate blood vessels, whhhich allows blood to flow more easily. These increase the blood flow without increasing the work of the heart. They're used to treat or prevent: High (hypertension) Heart flfailure. They are also used for the treatment of the diseases of coronary artery calle d pectoris. Amyl

C5H10ONO MOA: It is converted to (NO). Nitric oxide binds reversibly to the ferrous- center of ggyuanylate cyclase , causing conformational change and activating the . This enzyme activation results in increased cellular concentrations of cyclic guanosine monophosphate (cGMP) within the vascular smooth muscle, resulting in mediated by cGMP-dependent protein kinases. This process eventually leads increased blood flow in veins, arteries and cardiac tissue. Uses: Amyl nitrite is emppyloyed medically to treat heart diseases such as angina and to treat poisoning. Pentaerythritol tetranitrate O O

N+ N+ -OOO O-

O O -O O- N+ N+

O O MOA: Pentaerythritol tetranitrate is the lipid soluble polyol of nitric acid belonggging to the family of nitro-vasodilators. Pentaerythritol tetranitrate releases free nitric oxide (NO) after the denitration reaction. Nitric oxide binds reversibly to the ferrous-heme center of , causing conflformational change and activating theenzyme.This enzyme activation results in increased cellular concentrations of cyclic guanosine monophosphate (cGMP) within the vascular smooth muscle, resulting in vasodilation mediated by cGMP-dependent protein kinases. This process eventually leads increased blood flow in veins, arteries and cardiac tissue. Uses: Used for the treatment of angina pectoris.

IUPAC: 1,2,3-propantrioltrinitrate

MOA: It is converted to nitric oxide (NO). Nitric oxide binds reversibly to the ferrous-heme center of ggyuanylate cyclase , causing conformational change and activating the enzyme. This enzyme activation results in increased cellular concentrations of cyclic guanosine monophosphate (cGMP) within the vascular smooth muscle, resulting in vasodilation mediated by cGMP-dependent protein kinases. This process eventually leads increased blood flow in veins, arteries and cardiac tissue. Uses: It is indicated to prevent and treat angina or chest pain due to cardiovascular disease, as well as to treat peri-operative hypertension or induce intra-operative . It is also indicated to treat acute heart failure in patients with myocardial infarction. Isosorbide dinitrite

IUPAC: 6-nitrooxyhexahydrofuro[2,3-d]furan-3-yl] MOA: It is converted to nitric oxide(NO). Nitric oxide bdbinds reversibly to the ferrous-heme center of guanylate cyclase , causing conflformational change and activating theenzyme.This enzyme activation results in increased cellular concentrations of cyclic guanosine monophhhosphate (cGMP) within thevascular smooth muscle, resulting in vasodilation mediated by cGMP- dddependent protein kinases. This process eventually ldleads increased blood flow in veins, arteries and cardiac tissue. Uses: For theprevention of angina pectoris due to . CH2 OH HO O2NO H C OH H3C SO3H O HNO3 /H2SO4 O HO C H H C OH O O H C OH OH ONO2

CH2 OH D-sorbite isosorbide Dipyridamole OH N 5 4 N N 3N 6 OH HO N N N 7 2 8 1 N

OH IUPAC: 2-({6-[bis(2-hydroxyethyl)amino]-4,8-bis(piperidin-1-yl)- [1,3] diazino[5,4-d]pyrimidin-2-yl}(2-hydroxyethyl)amino)ethan-1-ol MOA: 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 phhliidhospholipidsand reduces thromb oxane A2 activity it . 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. Uses: Used in the prevention of postoperative thromboembolic complications of cardiac valve replacement and also used in prevention of angina.