SODIUM NITROPRUSSIDE

Once the methemoglobin supply is saturated, the remaining Cyanide- ions do what

- travels to the liver

Nitroprusside therapeutic use

Hypertensive emergencies • CHF

Nitroprusside route of administration

IV

thiocyanate toxicity presents as

anorexia, nausea, fatigue, disorientation, and psychosis

Nitroprusside drug interaction concerns

antihypertensive agents that may, when used concomitantly, lead to excessive hypotension. Also, agents with sympathomimetic activity may negate the effects of nitroprusside

What causes the incidence of thiocyanate toxicity to rise

prolonged administration of nitroprusside (>24 hours) and/or renal dysfunction

Nitroprusside is metabolized by

smooth muscle and erythrocytes upon entering the systemic circulation

In the liver Cyanide- ions are converted to______ at a rate of_____

thiocyanate, approximately 2 mcg/kg/min

Vessels Nitroprusside acts on

NO is released from nitroprusside equally in the venous and arterial circulation, nitroprusside does not appear to favor vasodilation in one side of the circulatory system over the other

What happens when Nitroprusside is metabolized

cyanide and then nitric oxide, NO then stimulates guanylyl cyclase, increasing cyclic GMP (cGMP) and leading to vasodilation

Nitroprusside binds______ and forms_______, and ______ is released in the process

hemoglobin, methemoglobin, 5 Cyanide- ions

Nitroprusside adverse effects

hypotension, reflex tachycardia, and worsening ischemia

Nitroprusside infusion may also worsen what in COPD patients

hypoxemia, by inhibiting arterial vasodilation and promoting ventilation-perfusion mismatch

Nitroprusside effect on oxygen demand of heart

lowers

One of the Cyanide- ions binds to ______ and forms _____

methemoglobin, cyanmethemoglobin

Nitroprusside effect on HR

minimal

Nitroprusside onset and half life

onset within seconds, half life of 2 minutes

Nitroprusside effect on regional bloodflow

preserves it

Nitroprusside Titration to rates above ________ are associated with toxicity

5 mcg/kg/min

Nitroprusside effect on healthy heart

Cardiac output decreased

Nitroprusside effect on diseased hearts

Cardiac output increased

Nitroprusside tolerance

Does not quickly develop