Analgesics - Week 13 PBL

Question 1

Two types of analgesics?

Answer 1

Opioids
Non-opioids (paracetamol, NSAIDs, Cox-2 inhibitors)

Question 2

Routes of administration for analgesics?

Answer 2

Oral, IV, subcutaneous, IM, topical

Question 3

Which pathway does NSAIDs affect?

Answer 3

Cox-1 and cox-2 enzymes

Both produce prostaglandins and induce inflammation;

Question 4

What are the risk of selective cox 2 inhibitors?

Answer 4

Risk of heart attack

Question 5

Mechanism of binding of opioid analgesics?

Answer 5

3 types of opioid receptors (M,D,K) (GPCRs)
Inhibit neurotransmission

Question 6

Effects of morphine?

Answer 6

CNS
Analgesia
Euphoria – particularly with iv adminstration
Sedation
Pupillary Constriction – stimulation of oculomotor nucleus brainstem

Gastrointestinal
Nausea and vomiting – chemoreceptor trigger zone in medulla
Constipation – from reduced motility and muscle tightening
Respiratory

Depression – inhibits respiratory centres in brainstem
Suppress cough reflex

Question 7

Safety issues with morphine?

Answer 7

Addiction
Desensitisation of receptors

Question 8

An opioid receptor antagonist?

Answer 8

Naloxone

Question 9

When to not prescribe opioids?

Answer 9

Neuropathic pain
Migraines
Chronic low back pain

Question 10

What else to prescribe with opioids?

Answer 10

Laxatives due to constipation

Question 11

Names of common opioids?

Answer 11

Morphine, codeine

Fentanyl or buprenorphine patches