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Isosorbide Dinitrate
- indication:For the prevention of angina pectoris due to coronary artery disease.
- pharmacologypharmacology:
- mechanism: Similar to other nitrites and organic nitrates, isosorbide dinitrate is converted to nitric oxide (NO), an active intermediate compound which activates the enzyme guanylate cyclase (atrial natriuretic peptide receptor A). This stimulates the synthesis of cyclic guanosine 3',5'-monophosphate (cGMP) which then activates a series of protein kinase-dependent phosphorylations in the smooth muscle cells, eventually resulting in the dephosphorylation of the myosin light chain of the smooth muscle fiber. The subsequent release of calcium ions results in the relaxation of the smooth muscle cells and vasodilation.
- toxicity: Symptoms of overdose include reduced cardiac output and hypotension.
- absorprion: Absorption of isosorbide dinitrate after oral dosing is nearly complete, but bioavailability is highly variable (10% to 90%), with extensive first-pass metabolism in the liver. The average bioavailability of isosorbide dinitrate is about 25%.
- halflife: 1 hour
- roouteelimination:
- volumedistribution: * 2 to 4 L/kg
- clearance: