How is mechanism of action of sodium nitroprusside?

• Sodium nitroprusside is a nitrodilator that acts as organic nitrates by releasingNO • Unlike organic nitrates, NO is liberated by non enzymatic process- Direct action on arterioles and venioles • NO activates the Guanylate cyclase pathway leading to the relaxation of thesmooth muscle and thus vasodilation. • Sodium nitroprusside is a nonselective vasodilator, it dilates both arteriolesand venules (unlike nitrates). It causes a reduction in myocardial O2 demand.