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