Morphine

Question 1

Drug class

Answer 1

Narcotic analgesic

Question 2

Pharmacology

Answer 2

Acts on the CNS by binding with opioid receptors, altering processes affecting pain perception & emotional response to pain.
It also combines to cause respiratory depression, vasodilation, decreases in gag reflex & slows AV node conduction.

Question 3

Metabolism

Answer 3

By the liver, kidneys & lungs

Question 4

Indications

Answer 4

• Significant pain
• Sedation
• Autonomic dysreflexia (Systolic BP >160)

*is the preferred narcotic agent except under the following circumstances:
• allergy and/or adverse drug reaction 
• haemodynamic instability 
• known/suspected kidney disease 
• when NAS narcotic admin is preferred 
• suspected ACS

Question 5

Contraindications

Answer 5

• Allergy and/or adverse drug reaction

* Kidney disease (renal failure)

Question 6

Precautions

Answer 6

• Low body weight, older or frail
• Hypotension
• Respiratory tract burns
• Respiratory depression and/or failure
• Known addiction to narcotics
• Concurrent MAOI therapy
• Cardiac chest pain

Question 7

Side effects

Answer 7

• Bradycardia
• Drowsiness
• Hypotension
• Nausea and/or vomiting
• Pin point pupils
• Respiratory depression

Question 8

Presentation

Answer 8

10mg/1ml amp

Question 9

Routes

Onset

Duration

Answer 9

SUBCUT / IM / IV

O: IM 5-10mins - peak 20-30min
IV 2-5mins - peak 20mins

D: 1-2hrs

Question 10

Special notes

Answer 10

• Situations in which morph & fentanyl are admin total max dose to be calculated using morphine milligram equivalent (MME) - 100mcg fent = 10mg morph
• CCP backup if pt hypotensive
• SBP <90 incremental dose not to be > 2.5mg IV or 5mg IM
• Single dose IM Morph can be used in moderate to severe labour pain in full term mums. Assess risks & benefits to mother & child - Morph will result in a degree of neonatal resp depression (transplacental transfer of morph is rapid & measurable within 5min. Imperative to notify hospital

Question 11

Adult dosages

Answer 11

** CONSULT - SUBCUT for significant pain

• Significant pain
• Autonomic dysreflexia (SBP >160)
▪︎≥70yrs
• IM 2.5-5mg, repeated at up to 5mg every 10mins, total max dose 10mg (or MME)
• IV 2.5mg, repeated at up to 2.5mg every 5mins, total max dose 10mg (or MME)

▪︎ <70yrs
• IM 2.5-10mg, repeated at up to 5mg every 10mins, total max dose 20mg (or MME)
• IV 2.5-5mg, repeated at up to 5mg every 5mins, total max dose 20mg (or MME)

Question 12

Paediatric dosages

Answer 12

• Consult <1yr
• • Consult - SUBCUT for significant pain

• Significant pain
• Autonomic dysreflexia (SBP >160)
 ≥ 1yr
▪︎IM
    100-200mcg/kg, single max dose 5mg
    Total max dose 200mcg/kg (or MME) 
▪︎IV 
    100mcg/kg, single max dose 2.5mg
    Repeated @ 50mcg/kg (max 2.5mg) at 5min intervals
   Total max dose 200mcg/kg (or MME)