TY  - CHAP
M1  - Book, Section
TI  - ISOPROTERENOL
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.
Y1  - 2018
N1  - 
T2  - Poisoning & Drug Overdose, 7e
AB  - Pharmacology.  Isoproterenol  is  a  catecholamine-like  drug  that  stimulates  beta-adrenergic  receptors  (beta1  and  beta2).  Its  pharmacologic  properties  include  positive  inotropic  and  chronotropic  cardiac  effects,  peripheral  vasodilation,  and  bronchodilation.  Isoproterenol  is  not  absorbed  orally  and  shows  variable  and  erratic  absorption  from  sublingual  and  rectal  sites.  The  effects  of  the  drug  are  terminated  rapidly  by  tissue  uptake  and  metabolism;  effects  persist  only  a  few  minutes  after  intravenous  injection.IndicationsSevere  bradycardia  or  conduction  block  resulting  in  hemodynamically  significant  hypotension  (Bradycardia  and  atrioventricular  (AV)  block).  Note:  After  beta-blocker  overdose,  even  exceedingly  high  doses  of  isoproterenol  may  not  overcome  the  pharmacologic  blockade  of  beta-receptors,  and  glucagon  is  the  preferred  agent.To  increase  heart  rate  and  thereby  abolish  polymorphous  ventricular  tachycardia  (torsade  de  pointes)  associated  with  QT-interval  prolongation  (Table  I–7).To  relieve  bronchospasm  (although  beta2-selective  drugs  such  as  albuterol  are  preferred).ContraindicationsDo  not  use  isoproterenol  for  ventricular  fibrillation  or  ventricular  tachycardia  (other  than  torsade  de  pointes).Use  with  extreme  caution  in  the  presence  of  halogenated  or  aromatic  hydrocarbon  solvents  or  anesthetics  or  chloral  hydrate.Adverse  effectsIncreased  myocardial  oxygen  demand  may  result  in  angina  pectoris  or  acute  myocardial  infarction.Peripheral  beta2-adrenergic-mediated  vasodilation  may  worsen  hypotension.The  drug  may  precipitate  ventricular  arrhythmias.Sulfite  preservative  in  some  parenteral  preparations  may  cause  hypersensitivity  reactions.Hypokalemia  may  occur  secondary  to  beta2-adrenergic-mediated  intracellular  potassium  shift.Use  in  pregnancy.  FDA  Category  C  (indeterminate).  This  does  not  preclude  its  acute,  short-term  use  for  a  seriously  symptomatic  patient  (Introduction).  However,  it  may  cause  fetal  ischemia  and  also  can  reduce  or  stop  uterine  contractions.Drug  or  laboratory  interactionsAdditive  beta-adrenergic  stimulation  occurs  in  the  presence  of  other  sympathomimetic  drugs,  theophylline,  and  glucagon.Administration  in  the  presence  of  cyclopropane,  halogenated  anesthetics,  or  other  halogenated  or  aromatic  hydrocarbons  may  enhance  the  risk  for  ventricular  arrhythmias  because  of  sensitization  of  the  myocardium  to  the  arrhythmogenic  effects  of  catecholamines.Digitalis-intoxicated  patients  are  more  prone  to  develop  ventricular  arrhythmias  when  isoproterenol  is  administered.Beta-blockers  may  interfere  with  the  action  of  isoproterenol  by  competitive  blockade  at  beta-adrenergic  receptors.Dosage  and  method  of  administrationFor  intravenous  infusion,  use  a  solution  containing  4  mcg/mL  (dilute  5  mL  of  1:5,000  solution  in  250  mL  of  D5W,);  begin  with  an  infusion  at  0.5–1  mcg/min  (children:  0.1  mcg/kg/min)  and  increase  as  needed  for  desired  effect  or  as  tolerated  (determined  by  monitoring  for  arrhythmias).  Usual  dosage  range  is  2–10  mcg/min.  For  emergency  treatment,  the  infusion  rate  may  start  at  5  mcg/min.  The  usual  upper  dose  is  20  mcg/min  (1.5  mcg/kg/min  in  children),  but  as  much  as  200  mcg/min  has  been  given  in  adults  with  propranolol  overdose.  Preparations  will  degrade  (and  turn  dark)  with  exposure  to  light,  air,  or  heat.For  IV  bolus,  the  usual  adult  dose  is  20–60  mcg  (1-3  mL  of  a  1:50,000  solution)  and  repeat  bolus  doses  of  10–200  mcg.  Make  a  solution  of  1:50,000  (20  mcg/mL)  by  diluting  1  mL  of  the  1:5,000  solution  to  a  volume  of  10  mL  with  normal  saline  or  D5W.FormulationsParenteral.  Isoproterenol  hydrochloride  (Isuprel,  others),  200  mcg/mL  (1:5,000)  in  1-  and  5-mL  ampules,  which  may  contain  sodium  bisulfite  or  sodium  metabisulfite  as  a  preservative.Suggested  minimum  stocking  levels  to  treat  a  100-kg  adult  for  the  first  8  hours  and  24  hours:  isoproterenol  hydrochloride,  first  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1179992973
ER  -