TY  - CHAP
M1  - Book, Section
TI  - MORPHINE
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.  Morphine  is  the  principal  alkaloid  of  opium  and  a  potent  analgesic  and  sedative  agent.  In  addition,  it  decreases  venous  tone  and  systemic  vascular  resistance,  resulting  in  reduced  preload  and  afterload.  Morphine  is  absorbed  variably  from  the  GI  tract  and  usually  is  used  parenterally.  After  intravenous  injection,  peak  analgesia  is  attained  within  20  minutes  and  usually  lasts  3–5  hours.  Morphine  is  eliminated  by  hepatic  metabolism,  with  a  serum  half-life  of  about  3  hours;  however,  the  clearance  of  morphine  is  slowed  and  the  duration  of  effect  is  prolonged  in  patients  with  renal  failure  resulting  from  accumulation  of  the  active  metabolite  morphine-6-glucuronide.IndicationsSevere  pain  associated  with  black  widow  spider  envenomation,  rattlesnake  envenomation,  and  other  bites  or  stings.Pain  caused  by  corrosive  injury  to  the  eyes,  skin,  or  GI  tract.Pulmonary  edema  resulting  from  congestive  heart  failure.  Chemically  induced  noncardiogenic  pulmonary  edema  is  not  an  indication  for  morphine  therapy.ContraindicationsKnown  hypersensitivity  to  morphine.Respiratory  or  CNS  depression  with  impending  respiratory  failure  unless  the  patient  is  already  intubated  or  equipment  is  available  and  trained  personnel  are  standing  by  for  intervention  if  necessary  with  intubation  or  the  reversal  agent  naloxone.Suspected  head  injury.  Morphine  may  obscure  or  cause  exaggerated  CNS  depression.Adverse  effectsRespiratory  and  CNS  depression  may  result  in  respiratory  arrest.  Depressant  effects  may  be  prolonged  in  patients  with  liver  disease  and  chronic  renal  failure.  Risk  factors  or  comorbidities  increasing  risk  for  morphine-induced  respiratory  depression  include  naive  user  lacking  tolerance,  hypothyroidism,  morbid  obesity,  and  sleep  apnea  syndrome.  Note:  Tidal  volume  may  be  depressed  without  perceptible  changes  in  respiratory  rate,  and  these  effects  are  influenced  by  external  stimuli  (eg,  noise,  manipulation).Hypotension  may  occur  owing  to  decreased  systemic  vascular  resistance  and  venous  tone.Nausea,  vomiting,  and  constipation  may  occur.Bradycardia,  wheezing,  flushing,  pruritus,  urticaria,  and  other  histamine-like  effects  may  occur.Sulfite  preservative  in  some  parenteral  preparations  may  cause  hypersensitivity  reactions.Use  in  pregnancy.  FDA  Category  C  (indeterminate).  This  does  not  preclude  its  acute,  short-term  use  in  a  seriously  symptomatic  patient  (Introduction).Drug  or  laboratory  interactionsAdditive  depressant  effects  with  other  opioid  agonists,  ethanol  and  other  sedative-hypnotic  agents,  tranquilizers,  MAO  inhibitors,  and  antidepressants.Naloxone  and  naltrexone  will  antagonize  the  analgesic  actions  of  morphine  and  may  precipitate  a  withdrawal  syndrome  in  morphine-dependent  patients.Morphine  is  physically  incompatible  with  solutions  containing  a  variety  of  drugs,  including  aminophylline,  phenytoin,  phenobarbital,  and  sodium  bicarbonate.Dosage  and  method  of  administrationMorphine  may  be  injected  subcutaneously,  intramuscularly,  or  intravenously.  The  oral  and  rectal  routes  produce  erratic  absorption  and  are  not  recommended  for  use  in  acutely  ill  patients.The  usual  initial  adult  dose  is  2–10  mg  IV  (may  dilute  with  4–5  mL  of  sterile  water  and  give  slowly  over  4–5  minutes  as  well  as  titrate  in  small  increments,  1–4  mg,  every  5  minutes)  or  10–15  mg  SC  or  IM,  with  maintenance  analgesic  doses  of  5–20  mg  every  4  hours.  The  usual  pediatric  dose  is  0.05-0.1  mg/kg  administered  very  slowly  IV  up  to  a  maximum  single  dose  of  10  mg,  or  0.1-0.2  mg/kg  SC  or  IM  up  to  a  maximum  of  15  mg.Note:  The  dosage  range  may  vary,  and  risk  factors  for  respiratory  depression  should  be  carefully  considered.  In  particular,  exercise  caution  in  morbidly  obese  patients  ...
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1179993003
ER  -