Morphine

CLASS

  • opioid analgesic

MECHANISM OF ACTION

  • mu and kappa receptor agonist
  • increase intracellular Ca2+ -> increased K+ conductance -> hyperpolarisation of excitable cell membranes -> decrease in pre & post synaptic responses
  • reversed by naloxone

PHARMACEUTICS

  • many routes of administration, clear, colourless solution for injection

DOSE

  • 0.1mg/kg IV (onset = 6 min, peak effect = 20 min)

INDICATIONS

  1. premed
  2. analgesic – visceral and skeletal muscle
  3. LVF
  4. symptomatic treatment of diarrhoea (combined with kaolin)

ADVERSE EFFECTS

  • hypotension
  • respiratory depression
  • bronchospasm
  • N+V
  • constipation
  • pruritis

PHARMACOKINETICS

  • Absorption – bioavailability = 40%
  • Distribution – 30% protein bound, Vd 4L/kg
  • Metabolism – hepatic, active metabolites
  • Elimination – urinary, t1/2 = 3 hrs, accumulates in renal failure

CCC Pharmacology Series

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the  Clinician Educator Incubator programme, and a CICM First Part Examiner.

He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.

His one great achievement is being the father of three amazing children.

On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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