Pain Management

Question 1

What class of drug is Morphine

Answer 1

Opioids

Question 2

Is Morphine syrup a controlled drug in Singapore?

Answer 2

No

Question 3

How is active morphine-6-glucuronide eliminated?

Answer 3

Renal

Question 4

Caution when using morphine

Answer 4

Patients with end organ damage of kidneys – risk of respiratory depression and extreme somnolence from renal accumulation of active metabolite

Question 5

Conversion of morphine to fentanyl patches

Answer 5

2mg (or 3.6mg) PO morphine = 1mcg/hr fentanyl patches

Question 6

How to transit from SA to LA for chronic pain?

Answer 6

Add 50-100% of total amount of SA used as prn to scheduled dose of LA

Question 7

Rescue prn doses are ________ of daily opioid requirements

Answer 7

10-20%

Question 8

How is opioid use disorder defined in CDC?

Answer 8

In the DSM-5 as a problematic pattern of opioid use leading to clinically significant impairment or distress

Question 9

For chronic pain, ____ doses are superior to ____ doses.

Answer 9

scheduled
PRN

Question 10

Onset of fentanyl

Answer 10

Fast onset

Question 11

Half life of Fentanyl

Answer 11

Short t1/2

Question 12

FDA definition of opioid tolerant

Answer 12

≥60mg Morphine or equivalent

Question 13

When to use fentanyl patches?

Answer 13

Patient is opioid tolerant

Question 14

Absorption in Fentanyl patches

Answer 14

Erratic; heat can increase absorption

Question 15

Onset of Fentanyl patches

Answer 15

Slower as compared to other routes
~8-12 hours
~2-3 days for full effect
SQ will form depot to diffuse Fentanyl slowly into bloodstream

Question 16

Duration for Fentanyl patches

Answer 16

q72 hours for most patients
for patients with wearing off effect, may require SA opioid for breakthrough pain moments

Question 17

Conversion of PO Morphine to Fentanyl Patch

Answer 17

1. 2mg PO Morphine = 1mcg/hr Fentanyl Patch
2. 3.6mg PO Morphine = 1mcg/hr Fentanyl Patch

Question 18

Consideration of patient factors when switching from PO Morphine to Fentanyl patches

Answer 18

• Patient’s ability to remove the patch
• Presence of cognitive impairment

Question 19

Methadone’s benefit

Answer 19

Can reverse potential tolerance to other opioids

Question 20

Half life of Methadone

Answer 20

Very long t1/2, counsel patients on potential variations on how they may feel day to day

Question 21

How is Methadone different from other opioids?

Answer 21

Does not produce euphoric effect → patients might be initially unwilling to switch from other opioids to Methadone

Question 22

Ketamine

Answer 22

• Inhibits NMDA receptor
• Works together with opioids to make them ‘supercharged’
• Difficult to use, many ADR and questionable efficacy in literature

Question 23

Opioid tolerance

Answer 23

Reduced response
Requiring more opioids (to experience same effect)

Question 24

Opioid dependence

Answer 24

Unpleasant physical symptoms when medication stopped

Question 25

Opioid addiction/OUD

Answer 25

Physically challenged to stop opioid use and increasing risk of withdrawal

Question 26

CDC guidelines not applicable for?

Answer 26

- Management of pain related to sickle cell disease - Management of cancer-related pain - Palliative care or end-of-life care

Question 27

Main CDC principle

Answer 27

opioids should be used only when benefits for pain and function are expected to outweigh risks

Question 28

When initiating opioid therapy, prescribe _____ opioids.

Answer 28

Immediate release

Question 29

Opioid - use caution when combining opioids with___________.

Answer 29

Benzodiazepines and other CNS depressants

Question 30

Step 1 of WHO's pain ladder

Answer 30

Non-opioid +/- adjuvants

Question 31

Step 2 of WHO's pain ladder

Answer 31

Opioid for mild-moderate pain +/- non-opioid +/- adjuvants

Question 32

Step 3 of WHO's pain ladder

Answer 32

Opioid for moderate-severe pain +/- non-opioid +/- adjuvants

Question 33

Mild to moderate pain

Answer 33

Weak opioids (codeine, tramadol) + non-opioids

Question 34

Moderate to severe pain

Answer 34

Discontinue weak opioids Consider starting strong opioids (morphine, fentanyl, oxycodone)

Question 35

Which opioid is a safer option in patients with moderate to severe renal and liver impairment?

Answer 35

Fentanyl

Question 36

Codeine is a prodrug of ______.

Answer 36

Morphine

Question 37

Caution use of Tramadol in ____?

Answer 37

Avoid use in severe H impairment Low dose required for R/H impairment and/or older persons

Question 38

Caution in Oxycodone

Answer 38

Increased risk of respiratory depression

Question 39

Caution in IM/IV tramadol

Answer 39

Patients with history of seizures

Question 40

Adjuvants for pain management

Answer 40

I. GABA Acting Anticonvulsants II. SNRIs III. Tramadol IV. Lidocaine Patches

Question 41

MOA of tramadol

Answer 41

1. serotonin reuptake inhibitor 2. norepinephrine reuptake inhibitor

Question 42

Which SNRI can be used as an adjuvant?

Answer 42

Duloxetine

Question 43

Which anticonvulsants can be used as an adjuvant?

Answer 43

- Gabapentin - Pregabalin

Question 44

End of Life Syndromes

Answer 44

a. Dyspnea b. Secretions c. Agitation/Delirium

Question 45

Management of dyspnea

Answer 45

Non-pharmacological - optimal breathing techniques, ensure airy environment, oxygen therapy for hypoxic patients Pharmacological - Morphine most commonly prescribed

Question 46

Management of secretions

Answer 46

1. Glycopyrrolate (anticholinergic) - not in SG 2. Hyoscine butylbromide (anticholinergic) - dry mouth, constipation and urinary retention