TY  - CHAP
M1  - Book, Section
TI  - NITROPRUSSIDE
A1  - Kearney, Thomas E.
A2  - Olson, Kent R.
A2  - Anderson, Ilene B.
A2  - Benowitz, Neal L.
A2  - Blanc, Paul D.
A2  - Clark, Richard F.
A2  - Kearney, Thomas E.
A2  - Kim-Katz, Susan Y.
A2  - Wu, Alan H. B.
PY  - 2018
T2  - Poisoning & Drug Overdose, 7e
AB  - Pharmacology.  Nitroprusside  is  an  ultra-short-acting,  titratable  parenteral  hypotensive  agent  that  acts  by  directly  relaxing  vascular  smooth  muscle  as  a  nitric  oxide  donor.  Both  arterial  dilation  and  venous  dilation  occur;  the  effect  is  more  marked  in  patients  with  hypertension.  A  small  increase  in  heart  rate  may  be  observed  in  hypertensive  patients.  Intravenous  administration  produces  a  nearly  immediate  onset  of  action,  with  a  duration  of  effect  of  1–10  minutes.  Resistance  may  occur  with  high  renin  activity.  Nitroprusside  is  metabolized  rapidly,  with  a  serum  half-life  of  about  1–2  minutes.  Cyanide  is  produced  during  metabolism  and  is  converted  to  the  less  toxic  thiocyanate.  Thiocyanate  has  a  half-life  of  2–3  days  and  accumulates  in  patients  with  renal  insufficiency.IndicationsRapid  control  of  severe  hypertension  (eg,  in  patients  with  stimulant  intoxication  or  monoamine  oxidase  inhibitor  toxicity).Arterial  vasodilation  in  patients  with  ergot-induced  peripheral  arterial  spasm.ContraindicationsCompensatory  hypertension—for  example,  in  patients  with  increased  intracranial  pressure  (eg,  hemorrhage  or  mass  lesion)  or  patients  with  coarctation  of  the  aorta.  If  nitroprusside  is  required  in  such  patients,  use  with  extreme  caution.Use  with  caution  in  patients  with  hepatic  insufficiency  because  cyanide  metabolism  may  be  impaired.Adverse  effectsNausea,  vomiting,  headache,  and  sweating  may  be  caused  by  excessively  rapid  lowering  of  blood  pressure.Cyanide  toxicity,  manifested  by  altered  mental  status  and  metabolic  (lactic)  acidosis,  may  occur  with  rapid  high-dose  infusion  (10-15  mcg/kg/min)  for  periods  of  1  hour  or  longer.  Patients  with  depleted  thiosulfate  stores  (eg,  malnourished)  may  have  elevated  cyanide  levels  at  lower  infusion  rates.  Continuous  intravenous  infusion  of  hydroxocobalamin,  25  mg/h  ,  or  thiosulfate  has  been  used  to  limit  cyanide  toxicity.  If  severe  cyanide  toxicity  occurs,  discontinue  the  nitroprusside  infusion  and  consider  antidotal  doses  of  thiosulfate  and  sodium  nitrite  or  high-dose  hydroxocobalamin.Thiocyanate  intoxication,  manifested  by  disorientation,  delirium,  muscle  twitching,  and  psychosis,  may  occur  with  prolonged  high-dose  nitroprusside  infusions  (usually  ≥3  mcg/kg/min  for  ≥48  hours),  particularly  in  patients  with  renal  insufficiency  (may  occur  at  rates  as  low  as  1  mcg/kg/min).  Thiocyanate  production  is  also  enhanced  by  coadministration  of  sodium  thiosulfate.  Monitor  thiocyanate  levels  if  the  nitroprusside  infusion  lasts  more  than  1–2  days;  toxicity  is  associated  with  thiocyanate  levels  of  50  mg/L  or  greater.  Usually  treat  by  lowering  the  infusion  rate  or  discontinuing  the  use  of  nitroprusside.  Thiocyanate  is  removed  effectively  by  hemodialysis.Rebound  hypertension  may  be  observed  after  sudden  discontinuance.Methemoglobinemia  may  be  observed  in  patients  receiving  more  than  10  mg/kg  but  is  typically  not  severe.Use  in  pregnancy.  FDA  Category  C  (indeterminate  Introduction).  It  may  cross  the  placenta  and  may  affect  uterine  blood  flow;  however,  it  has  been  used  successfully  in  pregnant  women.Drug  or  laboratory  interactions.  A  hypotensive  effect  is  potentiated  by  other  antihypertensive  agents  and  inhalational  anesthetics.Dosage  and  method  of  administrationUse  only  in  an  emergency  or  intensive  care  setting  with  the  capability  of  frequent  or  continuous  blood  pressure  monitoring.Dilute  the  50-mg  vial  (2  mL,  25  mg/mL)  of  sodium  nitroprusside  with  5%  dextrose  to  a  volume  of  250,  500,  or  1,000  mL  to  achieve  a  concentration  of  200,  100,  or  50  mcg/mL,  respectively.  Protect  the  solution  from  light  to  avoid  photodegradation  (as  evidenced  by  a  color  change)  by  covering  the  bottle  and  tubing  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1179993018
ER  -