TY  - CHAP
M1  - Book, Section
TI  - GLUCAGON
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.  Glucagon  is  a  polypeptide  hormone  that  stimulates  the  formation  of  adenyl  cyclase,  which  in  turn  increases  the  intracellular  concentration  of  cyclic  adenosine  monophosphate  (cAMP).  This  results  in  enhanced  glycogenolysis  and  an  elevated  serum  glucose  concentration,  vascular  smooth-muscle  relaxation,  and  positive  inotropic,  chronotropic,  and  dromotropic  effects.  These  effects  occur  independently  of  beta-adrenergic  stimulation  (glucagon  has  a  separate  receptor  on  the  myocardium)  and  seem  to  be  most  effective  at  increasing  the  heart  rate.  Glucagon  may  also  increase  arachidonic  acid  levels  in  cardiac  tissue  via  an  active  metabolite,  mini-glucagon.  Arachidonic  acid  improves  cardiac  contractility  owing  to  its  effects  on  calcium.  Glucagon  is  destroyed  in  the  GI  tract  and  must  be  given  parenterally.  After  intravenous  administration,  effects  are  seen  within  1–2  minutes  and  persist  for  10–20  minutes.  The  serum  half-life  is  about  3–10  minutes.  Note:  Glucagon  usually  is  not  considered  first-line  therapy  for  hypoglycemia  because  of  its  slow  onset  of  action  and  reliance  on  glycogen  stores.  Instead,  use  glucose  if  it  is  available.IndicationsHypotension,  bradycardia,  or  conduction  impairment  caused  by  beta-adrenergic  blocker  intoxication.  Also  consider  in  patients  with  hypotension  associated  with  anaphylactic  or  anaphylactoid  reactions  who  may  be  on  beta-adrenergic-blocking  agents.Possibly  effective  for  severe  cardiac  depression  caused  by  intoxication  with  calcium  antagonists,  tricyclic  antidepressants,  quinidine,  or  other  types  la  and  lc  antiarrhythmic  drugs.  Because  of  the  benign  side-effect  profile  of  glucagon,  consider  its  early  empiric  use  in  any  patient  with  myocardial  depression  (bradycardia,  hypotension,  or  low  cardiac  output)  who  does  not  respond  rapidly  to  usual  measures.To  facilitate  passage  of  obstructed  gastric  foreign  bodies  (eg,  drug  packets)  through  the  pylorus  into  the  intestine  (based  on  a  case  report).Contraindications.  Known  hypersensitivity  to  the  drug  (rare)  or  pheochromocytoma  (stimulates  the  release  of  catecholamines  and  may  result  in  severe  hypertension)  or  insulinoma  (indirectly  stimulates  release  of  insulin  and  may  result  in  hypoglycemia).Adverse  effectsHyperglycemia  (usually  transient),  hypokalemia.Nausea  and  vomiting  are  dose-dependent  (especially  if  >1  mg  is  administered)  and  caused  by  delayed  gastric  emptying  and  hypotonicity.Use  in  pregnancy.  FDA  Category  B.  Fetal  harm  is  extremely  unlikely  (Introduction).Drug  or  laboratory  interactions.  Concurrent  administration  of  epinephrine  potentiates  and  prolongs  the  hyperglycemic  and  cardiovascular  effects  of  glucagon.  It  is  unknown  whether  glucagon  interferes  with  the  effectiveness  of  insulin  and  glucose  therapy  for  severe  calcium  antagonist  poisoning.  Note  that  glucagon  stimulates  endogenous  insulin  secretion.Dosage  and  method  of  administration.Initial  dose.  Give  3–10  mg  IV  (may  also  titrate  with  0.05-mg/kg  boluses)  over  1–2  minutes  and  repeat  every  3–5  minutes  until  response  (usually  a  cumulative  total  of  10  mg,  but  up  to  30  mg  has  been  given).Maintenance  infusion.  Infuse  1–5  mg/h  (children:  0.15  mg/kg  IV,  or  titrate  with  0.05  mg/kg  every  3  minutes,  followed  by  0.05-0.1  mg/kg/h).  Alternatively,  determine  the  total  dose  required  to  achieve  the  initial  response  and  give  this  amount  every  hour.  Infusions  of  up  to  10  mg/h  have  been  used  for  adults.  Note:  Tachyphylaxis  may  occur  with  prolonged  infusions  (case  report  with  infusion  duration  >24  hours).For  very  large  doses,  consider  using  sterile  water  or  D5W  to  reconstitute  the  powder  rather  than  the  glycerine-containing  diluent  provided  with  the  drug  (eg,  add  4  mg  of  glucagon  to  50  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/16
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1179992953
ER  -