Neuropharmacology: Neurology, Pain And Analgesia

Question 1

What is the definition of pain

Answer 1

An unpleasant sensory and emotional experience associated with actual or potential tissue damage

Question 2

What are the types of pain

Answer 2

1. Nociceptive
2. Neuropathic
3. Psychogenic

Question 3

What is a nociceptive pain

Answer 3

Caused by stimulation of intact primary afferent nerves responding to stimuli approachin or exceedin the harmful intestiny (nociceptors)

Question 4

What is a neuropathic pain

Answer 4

Pain signal generated ectopically and often in the absence of ongoing noxious events by pathologic processes in the peripheral or central nervous system e.g diabetic get neuropathic pain

Question 5

What is pyscgogenic pain

Answer 5

Pain with no apparent organic bassis/strict diagnostic criteria

Question 6

What are pharmacological targets for pain

Answer 6

Source of pain
Nociceptive substance (prostaglandins and cytokines)
Nerve transmitter substance (serotonin)
Modulators in spinal cord and brain
Emotional reaction to pain

Question 7

What is the WHO pain ladder

Answer 7

Step 1: non opiod drug e.g paracetamol
Step 2: weak opiod if pain insists e.g codeine with non opiod
Step 3: strong opiod e.g morphine with non opiod

Question 8

What is the mechanism of paracetamol

Answer 8

Unknown but probably inhibits prostaglandins in CNS or modulates endogenous cannibinoids

Question 9

Does paracetomal have anti inflammatory action

Answer 9

No

Question 10

What is the mechanism of action of NSAIDs

Answer 10

Inhibitos of prostaglanding synthetase (cyclo-oxygenase)

Question 11

What are the 2 types of cyclo-oxygenase

Answer 11

Cox 1

Cox 2

Question 12

Where is cox 1 found

Answer 12

In the stomach it protects gastric mucosa

Question 13

Where is cox 2 found

Answer 13

Inducible inflammatory found in the renal tract

Question 14

Which enzyme inhibition are we intrested in for pain

Answer 14

Cox 2 that is involved in nociceptive pain

Question 15

What are the common NSAID examples

Answer 15

Ibuprofen

Diclofenac

Question 16

From the examples of NSAIDs which one is more stronger

Answer 16

Diclofenac

Question 17

What drugs can NSAIDs interact with

Answer 17

Anti-platelets and anticoagulants- increased risk of bleeding
Nephrotoxins- increased risk of acute kidney injury

Question 18

What are the side effects of NSAIDs

Answer 18

Cardiovascular risk
Renal dysfunction- AKI
Gastrointestinal bleding or gastritis
Hypersensitivity reaction: rashes, angioedema and bronchospasm

Question 19

In patients with a previous or active peptic ulcer what should NSAIDs be prescribed with

Answer 19

PPI

Question 20

What are examples of weak opiods

Answer 20

Codeine phosphate

Dihydrocodeine

Question 21

What is the mechanism of action for opiods

Answer 21

Act on the CNS to alter the perecepton of pain

Question 22

Do opiods have anti inflammatory affects

Answer 22

no

Question 23

What are the adverse effects of opoids

Answer 23

Nausea

Constipation

Question 24

Can codeine be used in children

Answer 24

No it is contraindicted

Question 25

What is tramadol

Answer 25

An opiod analgesic

Question 26

What is the mechanism of action of tramadol

Answer 26

Enhances 5HT and andregenic pathway

Question 27

What are the side effects of tramadol

Answer 27

Subject to abuse Respiratory Depression Hypotension Drowsiness

Question 28

What are examples of strong opiods

Answer 28

Morphine Fentanyl Oxycodone Pethidine

Question 29

What are the mechanism of action of strong opiods

Answer 29

Act on mu and kappa receptors in the cns

Question 30

Which group of patients should strong opiods be avoided in

Answer 30

``` Respiratory depression (type 2 respiratory failure) Hypotension Liver impairment (avoid in the elderly) ```

Question 31

What are adjuvant agents

Answer 31

Drugs that are intended for indication other than pain but are analgesics in certain circumstances

Question 32

At which step is adjuvant agents considered

Answer 32

Every step of the WHO ladder

Question 33

What are examples of adjuvant agents

Answer 33

Tricyclic anti depressants e.g amitryptiline Anti epileptic agents e.g pregabalin, gabapentin, carbamazepine Anxiolytics: diazepam

Question 34

What are the other modalities of pain management

Answer 34

Acunpuncture Transcutaenous electrical nerve stimulation (TENS) Topical anaesthesia Nerve block epidural

Question 35

In liver failure which drugs do we need to be aware of

Answer 35

NSAIDs- risk of bleeding | Opiods: can be slowly metabolised can precipitate encephalopathy in liver failure

Question 36

In renal disease which drug do we need to be aware of

Answer 36

NSAID- can lead to further impairment

Question 37

What is an issue with opiods

Answer 37

Dependence