TY  - CHAP
M1  - Book, Section
TI  - LIDOCAINE
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  - PharmacologyLidocaine  is  a  local  anesthetic  and  a  type  Ib  antiarrhythmic  agent.  It  inhibits  fast  sodium  channels  and  depresses  automaticity  within  the  His-Purkinje  system  and  the  ventricles  but  has  a  variable  effect  and  may  shorten  the  effective  refractory  period  and  action  potential  duration.  Conduction  within  ischemic  myocardial  areas  is  depressed,  abolishing  reentrant  circuits.  Unlike  quinidine  and  related  drugs,  lidocaine  exerts  a  minimal  effect  on  the  automaticity  of  the  sinoatrial  node  and  on  conduction  through  the  AV  node,  and  it  does  not  decrease  myocardial  contractility  or  blood  pressure  in  usual  doses.  It  also  has  rapid  "on-off"  binding  to  sodium  channels  (to  allow  reactivation  of  the  channel)  and  competes  with  other  sodium  channel  blockers  (that  are  slow  to  release  and  block  the  channel  throughout  the  cardiac  cycle).  This  may  account  for  its  antiarrhythmic  effect  with  poisonings  from  other  sodium  channel  blockers  (type  1a  antiarrhythmics,  tricyclic  antidepressants).The  oral  bioavailability  of  lidocaine  is  poor  owing  to  extensive  first-pass  hepatic  metabolism  (although  systemic  poisoning  is  possible  from  ingestion).  After  intravenous  administration  of  a  single  dose,  the  onset  of  action  is  within  60–90  seconds  and  the  duration  of  effect  is  10–20  minutes.  The  elimination  half-life  of  lidocaine  is  approximately  1.5–2  hours;  active  metabolites  have  elimination  half-lives  of  2–10  hours.  Lidocaine  clearance  declines  with  continuous  infusions,  which  may  be  attributable  to  its  metabolite  monoethylglycinexylidide  (MEGX).  Drug  accumulation  may  occur  in  patients  with  congestive  heart  failure  or  with  liver  or  renal  disease.Indications.  Lidocaine  is  used  for  the  control  of  ventricular  arrhythmias  arising  from  poisoning  by  a  variety  of  cardioactive  drugs  and  toxins  (eg,  digoxin,  cyclic  antidepressants,  stimulants,  and  theophylline).  Patients  with  atrial  arrhythmias  usually  do  not  respond  to  this  drug.ContraindicationsThe  presence  of  nodal  or  ventricular  rhythms  in  the  setting  of  third-degree  AV  or  intraventricular  block.  These  are  usually  reflex  escape  rhythms  that  may  provide  lifesaving  cardiac  output,  and  abolishing  them  may  result  in  asystole.Hypersensitivity  to  lidocaine  or  other  amide-type  local  anesthetics  (rare).Adverse  effectsExcessive  doses  produce  dizziness,  confusion,  agitation,  and  seizures.Conduction  defects,  bradycardia,  and  hypotension  may  occur  in  patients  with  extremely  high  serum  concentrations  or  in  those  with  underlying  conduction  disease.Use  in  pregnancy.  FDA  Category  B.  Fetal  harm  is  extremely  unlikely  (Introduction).Drug  or  laboratory  interactionsCimetidine  and  propranolol  may  decrease  the  hepatic  clearance  of  lidocaine.Lidocaine  may  produce  additive  effects  with  other  local  anesthetics.  In  severe  cocaine  intoxication,  lidocaine  theoretically  may  cause  additive  neuronal  depression.Dosage  and  method  of  administration  (adults  and  children)Administer  1-  to  1.5-mg/kg  (usual  adult  dose:  50–100  mg;  children:  1  mg/kg)  IV  bolus  at  a  rate  of  25–50  mg/min,  followed  by  infusion  of  1–4  mg/min  (20-50  mcg/kg/min)  to  maintain  serum  concentrations  of  1.5–5  mg/L.  Can  also  be  administered  by  intraosseous  infusion.If  significant  ectopy  persists  after  the  initial  bolus,  repeat  doses  of  0.5  mg/kg  IV  can  be  given  if  needed  at  5-  to  10-minute  intervals  (to  a  maximum  300-mg  or  3-mg/kg  total  dose  in  any  1-hour  period;  children  may  be  given  repeated  1-mg/kg  doses  every  5–10  minutes  to  a  maximum  of  5  mg/kg  or  up  to  100  mg).In  patients  with  congestive  heart  failure  or  liver  disease,  use  half  the  recommended  maintenance  infusion  dose.FormulationsParenteral.  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1174607476
ER  -