Opiates - Morphine

Question 1

What is morphine used for?

Answer 1

1) acute severe pain
2) chronic pian relief ( 3rd rung of WHO pain ladder)
3) relief of breathlessness
4) to relieve breathlessness and axiety in acute pulmonary oedema

Question 2

Morphine is used to releive breathlessness and anxiety in acute pulmonary oedema - what is it used alongside?

Answer 2

• morphine
• oxygen
• furosemide
• nitrates
  Are used together to treat acute pulmonary oedema

Question 3

What is the mechanism of action of morphine?

Answer 3

Morphine is a strong opiod,
Morphine activates opioid mu receptors in the CNS.
This reduces neuronal excitability and pain transmission.

• in medulla reduce redponse to hypoxia and hypercapnia –> so less breathlessness.

reduce sympathetic nervous system fight or flight activity*

• in an MI reduced cardiac work and oxygen demand.

Question 4

What are the side effects of morphine?

Answer 4

• respiratory depression
• euphoria / detachment
• neurological depression
• nausea / vomiting
• pupillary constriction
• constipation
• histamine release causes itching, sweating
• tolerance / dependence
• withdrawal reaction

Question 5

What are the contraindications of morphine?

Answer 5

• morphine is eliminated via the liver and kidneys so reduce dose in liver / kidney impairment and elderly
• don’t give in respiratory failure
• avoid in biliary colic as opioids cause spasm of sphincter of oddi.

Question 6

what is the initial dose of morphine?

Answer 6

2-10mg (IV if acute in HDU)

or IM/sub cut

Question 7

What is the dose and route of morphine for chronic pain?

Answer 7

• oral

- 5mg Oramorph every 4 hours then converted to modified release (15mg ever 12 hours)

Question 8

what antiemetic is prescribed with morphine?

Answer 8

metoclopramide

Question 9

what are the features of opioid withdrawal?

Answer 9

• anxiety
• pain
• breathlessness
• pupils dilate
• skin cool and dry, goodsebumps

Question 10

In acute coronary syndrome with ST elevation what is the immediate medical management?

Answer 10

Morphine + antiemetic, Oxygen, Aspirin Nitrates (MOAN)

• Morphine IV 5-10mg
• Metoclopramide 10mg IV
• Oxygen (15L high flow non rebreathe)
• Aspirin (300mg)
• Nitrates (GTN 2 sprays sublingual)
• thrombolysis / primary angioplasty
• beta blocker (atenolol 5mg IV)
• ACEi (ramipril 2.5mg)
• clopidogrel (300mg loading dose, followed by 75mg/day)