TY  - CHAP
M1  - Book, Section
TI  - ETHANOL
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.  Ethanol  (ethyl  alcohol)  acts  as  a  competitive  substrate  for  the  enzyme  alcohol  dehydrogenase,  preventing  the  formation  of  toxic  metabolites  from  methanol  or  ethylene  glycol.  A  serum  ethanol  concentration  of  100  mg/dL,  or  at  least  a  1:4  molar  ratio  of  ethanol  to  toxic  alcohol/glycol,  effectively  saturates  alcohol  dehydrogenase  and  prevents  further  methanol  and  ethylene  glycol  metabolism  (see  also  "Fomepizole  [4-Methylpyrazole,  4-MP]").  Ethanol  is  well  absorbed  from  the  GI  tract  when  given  orally,  but  the  onset  is  more  rapid  and  predictable  when  it  is  given  intravenously.  The  elimination  of  ethanol  is  zero  order;  the  average  rate  of  decline  is  15  mg/dL/h.  However,  this  is  highly  variable  and  will  be  influenced  by  prior  chronic  use  of  alcohol,  recruitment  of  alternate  metabolic  pathways,  and  concomitant  hemodialysis  (eg,  to  remove  methanol  or  ethylene  glycol).Indications.  Suspected  methanol  (methyl  alcohol)  or  ethylene  glycol  poisoning  with  the  following:A  suggestive  history  of  ingestion  of  a  toxic  dose  but  no  available  blood  concentration  measurements;Metabolic  acidosis  and  an  unexplained  elevated  osmol  gap;  orA  serum  methanol  or  ethylene  glycol  concentration  of  20  mg/dL  or  higher.Note:  Since  the  introduction  of  fomepizole  (4-methylpyrazole),  a  potent  inhibitor  of  alcohol  dehydrogenase,  most  patients  with  ethylene  glycol  or  methanol  poisoning  probably  will  be  treated  with  this  drug  instead  of  ethanol,  particularly  in  cases  involving  small  children,  patients  taking  disulfiram,  patients  with  pancreatitis,  and  hospitals  lacking  laboratory  support  to  perform  rapid  ethanol  levels  (for  monitoring  treatment).  Ethanol  is  more  difficult  to  dose,  requires  more  monitoring,  and  has  a  greater  risk  of  adverse  effects.  Studies  suggest  that  despite  the  higher  acquisition  costs  for  fomepizole,  it  may  be  more  cost-effective  than  ethanol.Other  substances  that  are  metabolized  by  alcohol  dehydrogenase  to  toxic  metabolites  include  propylene  glycol,  diethylene  glycol,  triethylene  glycol,  glycol  ethers  (eg,  ethylene  glycol  ethyl  ether,  ethylene  glycol  butyl  ether),  and  1,4-butanediol.  The  criteria  for  ethanol  therapy  and  evidence  for  improved  outcomes  are  lacking  for  these  substances.Contraindications.  Use  of  interacting  drugs,  which  may  cause  disulfiram-type  reaction  (see  Item  V.  B  below).Adverse  effectsNausea,  vomiting,  and  gastritis  may  occur  with  oral  administration.  Ethanol  may  also  exacerbate  pancreatitis.Inebriation,  sedation,  and  hypoglycemia  (particularly  in  children  and  malnourished  adults)  may  occur.Intravenous  use  sometimes  is  associated  with  local  phlebitis  (especially  with  ethanol  solutions  10%).  Hyponatremia  may  result  from  large  doses  of  sodium-free  intravenous  solutions.Acute  flushing,  palpitations,  and  postural  hypotension  may  occur  in  patients  with  atypical  aldehyde  dehydrogenase  enzyme  (up  to  50-80%  of  Japanese,  Chinese,  and  Korean  individuals).Use  in  pregnancy.  FDA  Category  C  (indeterminate).  Ethanol  crosses  the  placenta.  Chronic  overuse  in  pregnancy  is  associated  with  birth  defects  (fetal  alcohol  syndrome).  The  drug  reduces  uterine  contractions  and  may  slow  or  stop  labor.  However,  these  effects  do  not  preclude  its  acute,  short-term  use  for  a  seriously  symptomatic  patient  (Introduction).Drug  or  laboratory  interactionsEthanol  potentiates  the  effect  of  CNS-depressant  drugs  and  hypoglycemic  agents.Disulfiram  reaction,  including  flushing,  palpitations,  and  postural  hypotension,  may  occur  in  patients  taking  disulfiram  as  well  as  a  variety  of  other  medications  (eg,  metronidazole,  furazolidone,  procarbazine,  chlorpropamide,  some  cephalosporins,  and  Coprinus  mushrooms).  In  such  cases,  fomepizole  is  the  recommended  alternative  to  ethanol  treatment.Drugs  or  chemicals  metabolized  by  alcohol  dehydrogenase  (eg,  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1174607432
ER  -