Analgesics and Sedative Drugs

Question 1

What is pain?

Answer 1

an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage

Question 2

Anagesia

Answer 2

relieve pain by directly manipulating its physiological mechanisms

Question 3

Pain cam be assessed using

Answer 3

unidimensional tools like scales/faces

multi-dimensional tools (more history)

Question 4

What is an adjuvent?

Answer 4

Enhancing effect of a drug

Question 5

WHO Analgesic Ladder:

Answer 5

• needs to be bidirectional
• step 4 = minimally invasive procedures

Question 6

Principles of WHO Analgesic Ladder:

Answer 6

• by the mouth = oral administration
• by the clock = regular and at regular
  intervals
• by the ladder = according with the pain
  intensity characterised by the patient
• individualised therapy = dosing
• medication adherence

Question 7

Analgesia can be complicated:

Answer 7

insert slide

Question 8

NSAIDs:

Answer 8

• non-steroidal anti-inflammatory drug
• ibuprofen
• effects can be peripheral and central
• competitive inhibitors of COX

Three Effects:
- analgesics
- anti-inflammatory
- antipyretic

Question 9

Core Drug: Ibuprofen: Mechanism of Action:

Answer 9

Competitive inhibitors of COX

(reversible action)

hence:
- reduce production of prostaglandins
- prostaglandins increase Na+/Ca2+
influx into nociceptors, hence
decreasing pain signalling

Question 10

Core Drug: Aspirin: Mechanism of Action:

Answer 10

irreversible inhibitor of COX

lowers amount of time needs to be taken

COX1 in platelets, platelets have no nucleus so can not synthetise new COX1

Question 11

Arachidonic Acid

Answer 11

insert flowchart

Question 12

Effects of NSAIDs:

Answer 12

insert flowchart (17)

Question 13

Side Effects of Ibuprofen:

Answer 13

• perforation
• peptic ulcers
• renal failure
• fluid retention
• constipation

Question 14

How to avoid gastric pain from taking NSAIDs?

Answer 14

Proton Pump Inhibitors PPIs

omneprazole

Question 15

Is paracetamol an NSAID?

Answer 15

No only an analgesic and antipyretic not an anti-inflammatory

Question 16

Core Drug: Paracetamol: Drug Class:

Answer 16

Analgesic

Question 17

Core Drug: Paracetamol: Mechanism of Action:

Answer 17

• inhibition of COX

Question 18

Core Drug: Paracetamol: Effects:

Answer 18

mainly central
benefit from regular full dosing

Question 19

Core Drug: Paracetamol: Metabolised:

Answer 19

Liver

Question 20

Core Drug: Paracetamol: Side Effects:

Answer 20

• patients with liver failure
• liver impairment
• adverse effects are rare

NO INJURY TO GASTRIC MUCOSA

Question 21

What is the primary drug class for acute management of moderate to severe pain?

Answer 21

Opiods (agonist of opiod receptors)

Question 22

What type of receptors are responsible for most analgesic effects of opiods?

Answer 22

mu opiod receptors
coupled to G alpha i

Question 23

Opiod Receptors: Mechanism of Action:

Answer 23

• bind to opiod receptors
• activate G-alpha-i pathway
• inhibition of adenylate cyclase, decrease
  in cyclic AMP, decreased
  phosphorylation
• inhibits Ca2+ voltage gated channels,
  leading to decreased release of
  neurotransmitters
• activates K+ channels, which
  hyperpolarise cell membranes, less APs
  fired

Question 24

An example of a weak opiod?

Answer 24

Core Drug: Codeine

Question 25

Codeine: Ceiling Dose:

Answer 25

- pain relief will stop after a certain dose - continuing will simply increase risk or intensity of the adverse reactions

Question 26

Does morphine have a ceiling dose?

Answer 26

No

Question 27

Core Drugs: How potent is codeine compared to morphine?

Answer 27

1/10th as potent as morphine

Question 28

Core Drug: Codeine: Metabolism:

Answer 28

metabolised to morphine by the liver

Question 29

Core Drug: Morphine: Metabolism:

Answer 29

- metabolised to active metabolites - renally excreted can cause renal impairment

Question 30

Core Drug: Codeine: Side Effects:

Answer 30

- constipation = faecal softener + stimulant laxative (no) - nausea and vomiting = antiemetics (yes) - sedation - confusion = reduce dose + monitor renal function - respiratory depression = naloxone

Question 31

Opiod Toxicity: Management:

Answer 31

- initial management: - reduce dose - hydrate - relieve agitation with low dose of haloperidol - if intolerant side effects with inadequate pain relief switch to an alternative analgesic - naloxone (with caution)

Question 32

Naloxone

Answer 32

- opiod antagonist - all opiod receptors (many side effects)

Question 33

Sedation: Pharmacological Management:

Answer 33

- opiods - propofol - dexmedetomidine - benzodiazepine: diazapam - Z-drugs; Zopiclone

Question 34

Core Drug: Diazepam: Mechanism of Action:

Answer 34

- GABA receptor modulator (ionotropic) - bind in different site to GABA - GABA still needed for effect - simply facilitating the opening of channel - Cl- channel - hyperpolarise cell, stable and resting - depressive effect on the nervous system

Question 35

Core Drug: Diazepam: Side Effects:

Answer 35

- oversedation - drowsiness - light-headedness - amnesia - muscle weakness - tolerance - dependance (need withdrawal management)

Question 36

Core Drug: Zopiclone: Mechanism of Action:

Answer 36

- GABA receptor modulator (ionotropic) - bind in different site to GABA - GABA still needed for effect - simply facilitating the opening of channel - Cl- channel - hyperpolarise cell, stable and resting - depressive effect on the nervous system

Question 37

Core Drug: Zopiclone: Side Effects:

Answer 37

- dry mouth*** - metallic taste in mouth*** - oversedation - drowsiness - light-headedness - confusion - amnesia - muscle weakness - tolerance - dependence