Pharmacology - Bone Pain Flashcards Preview

MBBS - Year 1 > Pharmacology - Bone Pain > Flashcards

Flashcards in Pharmacology - Bone Pain Deck (55)
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1
Q

CD

A

Controlled drug

2
Q

PO

A

Orally

3
Q

IV bolus

A

Single, small quantity given over small period of time into vein

4
Q

IV infusion

A

Larger quantity infused/ given over a longer time into vein

5
Q

SL

A

Sublingual

6
Q

Intrathecal

A

Into the spine

7
Q

Chemical structure of opioids

A

Activity comes from free hydroxyl on benzene ring, linked by w carbon atoms to a nitrogen

8
Q

How are variations of morphine made

A

Substitutions made at one of both the hydroxyls to give diamorphine and oxycodone

9
Q

Pharmacodynamics of opioids

A
Analgesia 
Euphoria 
Respiratory depression 
Cough suppression 
Pin-point pupils 
Nausea and vomiting 
Constipation 
Bronchospasm, hypotension, local itchiness
10
Q

Analgesia - opioids

A

Used for acute/ chronic pain

Not used for neuropathic pain

11
Q

Euphoria - opioids

A

Sense of wellbeing & contentment (μ receptor)
Dysphoria/ hallucinations к-receptor
Helps w/ analgesia as minimises the agitations and anxiety associated w/ pain/ trauma

12
Q

Respiratory depression - opioids

A

Medicated by μ receptor, decrease sensitivity of respiratory centre to arterial Pco2 levels and inhibition of respiratory rhythm generation
Commonest cause of death in acute opioid poisoning

13
Q

Pin-point pupils - opioids

A

μ + к receptor stimulation.

14
Q

Nausea and vomiting - opioids

A

Common SE, 40% pts, however transient SE

15
Q

Constipation - opioids

A

Increase tone and reduce gut motility = constipation

Also reduces drug absorption

16
Q

Bronchospasm - opioids

A

Histamine is released in states of allergy (e.g. hay fever)
Morphine releases histamine from mast cells
Local irritation
Bronchospasm in asthmatics = bad combo!

17
Q

Tolerance

A

Increasing dose to get same pharmalogical response; develops within a few days. This means in palliative care we have to keep swapping drugs.

18
Q

Switching between opioids

A

Opioids cannot be used interchangeably
Follow palliative care guidance in BNF
Use local/ trust guideline

19
Q

What causes withdrawal symptoms

A

Physical dependence on drug

μ receptor agonist removal

20
Q

Relieving withdrawal symptoms

A

Long acting μ receptor agonists (methadone/buprenorphine

21
Q

Why do we have CDs

A

Misuse of drugs act 1971 (manufacture/ supply/ possession)

22
Q

Class A drugs

A

Heroin
Cocaine
LSD
Methadone

23
Q

Class B drugs

A

Barbituates

Cannabis

24
Q

Class C drugs

A

Buprenorphine

Anabolic steroids

25
Q

Level 1 - WHO pain relief ladder

A

Pain persisting or increasing

Non-opioid +/- adjuvant

26
Q

Level 2 - WHO pain relief ladder

A

Opioid for mild to moderate pain
+/- non-opioid
+/- adjuvant

27
Q

Level 3 - WHO pain relief ladder

A

Opioid for moderate to severe pain
+/- non-opioid
+/- adjuvant

28
Q

Non-opioid in pain ladder

A

Paracetamol

29
Q

Adjuvants in pain ladder

A

NSAIDs e.g. ibuprofen, diclofenac

30
Q

Mild opioid

A

Codeine
Dihydrocodeine
Tramadol

31
Q

Mod-severe opioid

A

Morphine

32
Q

Mechanism of action of NSAIDs

A

Inhibits cyclo-oxygenase (COX) enzymes 1, 2 which convert arachidonic acid to prostaglandins and leukotrienes by the COX and 5-lipoxygenase pathways respectively

33
Q

COX-1

A

Produces prostaglandins that protect against mucosal damage and regulates platelet aggregation and renal blood flow

34
Q

COX-2

A

The prostaglandins here cause local pain + swelling. Inflammation also increases COX-2 production in the spinal cord where pain signals are processed

35
Q

Non-selective inhibitors

A

NSAIDs that act on COX-1 AND COX-2 (ibuprofen, naproxen)

Higher risk of stomach ulcers

36
Q

Selective inhibitors

A

NSAIDs that only act on COX-2 (celecoxib, etoricoxib)

37
Q

Therapeutic effects of NSAIDs

A
Anti-inflammatory = ↓Prostaglandin E2 and Prostacyclin
Analgesic= ↓Prostaglandins
Antipyretic= ↓Interleukin-1
38
Q

-ve effects of NSAIDs

A
Stomach= acid gets through lining, unable to make protective mucosa, creates ulcer
Platelet activity= less clotting, more GI bleeds
39
Q

Contraindications of NSAIDs

A
Severe heart failure or liver disease
Asthma
Hx peptic ulcer
Hx gastrointestinal bleeding
Adverse event with NSAIDs
40
Q

Mechanism of action of paracetamol

A

Weak COX inhibitor, so doesn’t exhibit anti-inflammatory effect
Assumed to selectively inhibit COX-3 enzyme (mechanism not fully understood)

41
Q

Contraindications of paracetamol

A

Hx of allergic reaction

42
Q

Compound painkillers

A

Compound painkillers are made from a combination of 2 drugs- usually a standard painkiller and low dose of an opioid

43
Q

Examples of compound painkillers

A
Co-codamol= paracetamol + codeine
Co-codaprin= aspirin + codeine
Co-dydramol= paracetamol + dihydrocodeine
44
Q

Most effective antidepressants

A

TCAs and SNRIs (tricyclic antidepressants and serotonin-norepinephrine reuptake inhibitors)

45
Q

TCAs and SNRIs

A

Affect transmission of both NTs serotonin and norepinephrine –> reduces pain at a spinal and cerebral level

46
Q

What are anti-depressants effective in treating depression and chronic pain

A

The same parts of the brain are affected in people with major depressive disorders

47
Q

Contraindications of antidepressants

A

Arrhythmias
Manic phase of bipolar disorder
Heart block
Immediate recovery period after M.I

48
Q

Types of opioid receptors

A

Mu
Delta
Kappa
NOP

All G-coupled receptors and cause hyper polarisation of neurones —> reducing in firing of AP

49
Q

Mu opioid receptors

A

Responsible for most analgesic effects but also the worst side effects

50
Q

Delta opioid receptors

A

Analgesia but can also be proconvulsant

51
Q

Kappa opioid receptors

A

Analgesia at spinal level, may cause sedation, dysphoria + hallucinations

52
Q

NOP opioid receptors

A

Reverse effects of mu receptor agonists (supraspinal), analgesia (spinal), immobility + learning impairment

53
Q

Contraindications of opioids

A
Acute respiratory depression
Comatose patients
Head injury
Raised intracranial pressure
Risk of Paralytic ileus
54
Q

Side effects of opioids

A

Arrythmias, confusion, constipation, dizziness, drowsiness, dry mouth, euphoric mood, flushing, hallucinations, headache, hyperhidrosis, hypotension, nausea, palpitations, respiratory depression, skin reactions, urinary retention, vertigo, visual impairment, vomiting, withdrawal syndrome

55
Q

Action of opioids

A

Cross blood-brain barrier and access CNS to have central action

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