Pharmacology

Question 1

Where can analgesics act?

Answer 1

Site of injury- Decrease sensitisation by decreasing prostaglandins
Block nerve conduction- Block Na channels (lidocaine)
Block synapse transmission in dorsal horn
Activate inhibitory descending path
Ion channels upregulated in nerve damage

Question 2

What are the rungs of the analgesic ladder?

Answer 2

NSAIDs/paracetamol
Weak opioid
Strong opioid

Question 3

Give some examples of NSAIDs

Answer 3

Aspirin
Diclofenac
Ibruprofen

Question 4

Give some examples of weak opioids

Answer 4

Codeine

Tramadol

Question 5

Give some examples of strong opioids

Answer 5

Morphine

Oxycodone

Question 6

Whats the difference between opiates and opioids?

Answer 6

Opiates- Substances from or structurally similar to opium.

Opioids- Anything acting on opioid receptors

Question 7

What are endogenous opioids called?

Answer 7

Enkephalins

Question 8

How does the body naturally modulate nociception?

Answer 8

Descending pathways from the brainstem (Supraspinal Antinociception)

Question 9

Where does the Supraspinal Antinociception system arise?

Answer 9

Periaqueductal grey (midbrain)

Question 10

Where does the supraspinal antinociception system ultimately project to?

Answer 10

Spinal cord

Question 11

Where does the PAG project to?

Answer 11

Locus ceruleus (pons)
Nucleus raphe magnus (medulla)

Question 12

What activates the PAG?

Answer 12

Opioids and electrical input

Question 13

What does activation of nucleus raphe magnus do?

Answer 13

Release 5-HT (serotonin) and enkephalins onto dorsal horn to modulate nociception.

Question 14

What chemical can activate the NRM?

Answer 14

Opioids (morphine)

Question 15

What does activation of the locus ceruleus do?

Answer 15

Release NA onto dorsal horn to modulate nociception.

Question 16

What kind of receptors are opioid receptors?

Answer 16

GCPR

Question 17

What kind of GCPR are opioid receptors?

Answer 17

Gi/o

Question 18

What does activation of GCPR do?

Answer 18

Inhibit presynaptic VGCC channel opening (By SU. Block vesicle release).
Open postsynaptic K+ channels to hyperpol (By SU)
Inhibit adenylate cyclase (a SU. Needed for long term effects)

Question 19

What are the three main categories of opioid receptor?

Answer 19

Mu- Main but lots of side effects
Delta
Kappa

Question 20

What are some side effects of opioids?

Answer 20

Addiction
Resp depression
Constapation
N+V
Orthostatic hypotension
Confusion
Hallucinations

Question 21

Name six key opioid R agonists

Answer 21

Mrorphine
Diamorphine
Codeine
Fentanyl
Tramadol
Methadone

Question 22

How can morphine be given?

Answer 22

IV
Oral
IM
Subcut

Question 23

What receptor does morphine preferentially act on?

Answer 23

Mu

Question 24

Where is morphine metabolised?

Answer 24

Liver

Question 25

What is a difference between morphine and diamorphine?

Answer 25

Diamorphine is more lipophilic

Question 26

How does codeine compare to morphine?

Answer 26

Weaker

Question 27

How is codeine usually given?

Answer 27

Orally

Question 28

IN addition to analgesia what other effects does codeine have?

Answer 28

Anti-diarrhoeal | Antitussive

Question 29

What are two variations of codeine?

Answer 29

Oxycodone | Hydrocodone

Question 30

How does fentanyl compare to morphine?

Answer 30

100x more potent

Question 31

When and how is fentanyl used?

Answer 31

IV for maintenance analgesia | Transdermal for chronic pain

Question 32

Describe tramadol

Answer 32

Weak muR agonist. | Most effects by activating NRM

Question 33

What patient group should avoid tramadol?

Answer 33

Epileptics

Question 34

Describe methadone

Answer 34

Weak mu R agonist. Long half life. | Good for chronic pain and addiction

Question 35

Name two important opioid receptor antagonists

Answer 35

Naloxone | Naltrexone

Question 36

How does naloxone work?

Answer 36

Competitive mu antagonist

Question 37

When is naloxone used?

Answer 37

To reverse opioid toxicity. Short HL so must monitor closely to check doesn't wear off too quickly. Newborn babies with opioid toxicity from birth process

Question 38

Describe naltrexone

Answer 38

Similar to naloxone but longer HL and oral availability

Question 39

Broadly how do NSAIDs work?

Answer 39

Decrease nociceptor sensitisation

Question 40

When are NSAIDs used?

Answer 40

To treat mild inflammatory pain

Question 41

What effects do NSAIDs have?

Answer 41

Analgesic Antipyretic Anti Inflammatory

Question 42

How do NSAIDs decrease nociceptor sensitisation

Answer 42

By decreasing prostaglandin synthesis

Question 43

Which enzymes do NSAIDs inhibit to block prostaglandin synthesis?

Answer 43

COX1 and 2

Question 44

What do prostaglandins do?

Answer 44

Hyperalgesia Allodynia Pain

Question 45

What is the difference between COX1 and 2

Answer 45

COX1 always active | COX2 only activated locally to damage by cytokines

Question 46

Is paracetamol a NSAID and why?

Answer 46

No because it doesn't have any anti-inflammatory effects

Question 47

Where does paracetamol work?

Answer 47

Centrally

Question 48

What is neuropathic pain?

Answer 48

Pain from damaged nerves

Question 49

Does neuropathic pain respond to NSAIDs and opioids?

Answer 49

No

Question 50

What does neuropathic pain respond to?

Answer 50

Gabapentin Pregabalin Amitriptyline Carbamazepine

Question 51

How do gabapentin and pregabalin work?

Answer 51

Decrease the expression of the a2d SU of VGCC which is upregulated in damaged sensory nerves

Question 52

Name a condition gabapentin is used for

Answer 52

Migraine profolaxis

Question 53

Name a condition pregabalin is used for

Answer 53

Diabetic neuropathy

Question 54

How does amitriptyline work?

Answer 54

Decrease reuptake of NA

Question 55

How does carbamazepine act?

Answer 55

Blocks VGNC subtype that is upregulated in damaged nerves.