Sodium nitroprusside is metabolized to form an active metabolite. This active metabolized to form an active metabolite. This active metabolite of sodium nitroprusside act activation of:
Phospholipase A
Phospholipase C
Guanylate cyclase
Protein Kinase C
Nitoprusside and nitrates act by production of NO (nitric oxide). NO stimulates guanylate cyclase in smooth muscles which leads to formation of cGMP. cGMP act on smooth muscles to cause vasodilation.