Neuropharmacology

Question 1

What is nociceptive pain?

Answer 1

Pain that is due to stimulation of nociceptors- produced due to stimulus that can cause tissue damage

Question 2

What is neuropathic pain?

Answer 2

Pain the is not due to a stimulus, occurs in the absences of an ongoing noxious event

Question 3

What is allodynia?

Answer 3

Painful responses to non-painful stimuli

Question 4

What is hyperalgesia?

Answer 4

Pain is felt more strongly

Question 5

What is the WHO pain ladder?

Answer 5

Non-opiate
Weak opiate
Strong opiate
(Titrate up and down as required)

Question 6

What are the features of paracetemol?

Answer 6

Reduces mild pain
Anti-pyretic- reduces fever
No anti-inflammatory reaction

Question 7

How do NSAIDs produce pain relief?

Answer 7

COX-2 Inhibition

COX-1 inhibition is an off-target response which reduces the production of the protective lining of the gastric mucosa

Question 8

What are the features of NSAIDs?

Answer 8

Reduce inflammatory pain
No anti-pyrexial action
Nephrotoxic

Question 9

Name two NSAIDs

Answer 9

Aspirin
Diclofenac - most potent
Ibuprofen

Question 10

What are some risks with NSAID treatment?

Answer 10

Asthma trigger
Hypersensitivity reactions- Aspirin should not be given to children due to Reye’s reaction
Peptic ulcer formation
GI bleed
Reduced clotting due to anti-platelet action
Nephrotoxic

Question 11

What should be given when prescribing an NSAID to a patient with an active or previous history of peptic ulcer diseasE?

Answer 11

A PPI

E.g. Lansoprazole

Question 12

Give an example of a weak opiod

Answer 12

Codeine

Question 13

Do opiates have any anti-inflammatory action?

Answer 13

No they do not

NSAIDs do this

Question 14

What is a contra-indication to codeine?

Answer 14

Breast feeding as it can be excreted into the breast milk

Question 15

What are some side effects of codeine?

Answer 15

Sedation
Constipation
Nausea

Question 16

What is the mechanism of tramadol?

Answer 16

Opioid analgesic that also enhances 5HT and adrenergic pathways- causes euphoria so is subject to abuse

Question 17

Give an example of a strong opiate

Answer 17

Morphine
Fentanyl
Pethidine

Question 18

What is the mechanism of action of opiates?

Answer 18

Act on the mu and kappa receptors in the CNS

Question 19

Why are strong opiates subject to abuse?

Answer 19

Tolerance develops which leads to withdrawal symptoms when removed

Question 20

What is an adjuvant agent?

Answer 20

Drug intended for indications other than pain but are analgesic in selected circumstances
Generally used at lower doses than their usual indications

Question 21

Give three examples of adjuvant agents

Answer 21

Tricyclic antidepressants- Amitriptyline
Anti epileptic drugs- Carbamazepine, Gabapentin
Anxiolytics- Benzodiazepam

Question 22

What are some side effects of TCAs?

Answer 22

Example Amitriptyline
Sedation
Drowsiness
Amtimuscarinic effects- dry mouth, urinary retention
Dangerous in overdose

Question 23

How does lamotrigine work?

Answer 23

Reduces pre-synaptic release of glutamate
Inhibits sodium channels
Used for all types of epilepsy
Safe to use in pregnancy

Question 24

How does carbamazepine work?

Answer 24

Blocks sodium channels, prevents excitation
Safe to use in pregnancy
Used for tonic-clonic seizures

Question 25

How do barbiturates work?

Answer 25

Barbiturates include phenobarbitol
They increase GABA signalling
Used for all types of epilepsy except absence seizures

Question 26

How does benzodiazepine work

Answer 26

Increases GABA signalling

Used for status epilepticus- IV lorazepam/ rectal diazepam

Question 27

How does valproate work?

Answer 27

Blocks GABA-T and so reduces breakdown of GABA
Not safe to use during pregnancy
Used for partial, tonic clonic and absence

Question 28

How does vigabatrin work?

Answer 28

Blocks GABA-T and so reduces breakdown of GABA

Question 29

How does tiagabine work?

Answer 29

Reduces re-uptake of GABA and so increases concentrations in the synaptic cleft

Question 30

How does topiramate work?

Answer 30

Reduces glutamate signalling through action on the AMPA receptor

Question 31

How does felbamate work?

Answer 31

Reduces glutamate signalling through action on NMDA receptor

Question 32

How does phenytoin work?

Answer 32

Inhibition of sodium and calcium channels

Used for status epliepticus

Question 33

How does ethosuximide work?

Answer 33

Inhibition of calcium channels