IC6 Supportive and Palliative Care (Pain mgmt) Flashcards
Briefly describe the 3 steps in the pain ladder
- Step 1 (pain persisting or increasing) → non-opioid +/- adjuvant
- Step 2 (pain persisting or increasing → opioid for mild to moderate pain +/- non-opioid +/- adjuvant
- Step 3 (freedom from cancer pain) → opioid for moderate to severe pain +/- non-opioid +/- adjuvant
What is a good guiding percentage of round-the-clock scheduled doses to give, using PRN opioid doses as a baseline?
Generally, add 50% to 100% of PRN usage to around the clock scheduled doses
i.e. if patient usually requires 100mg of X as PRN management, consider changing to 150-200mg LA of X, while maintaining 100mg X PRN
What percentage of rescue PRN dosing should account for daily opioid requirement?
10-20%
Why are opioid conversion tables not always the most reliable?
Most of these equivalent doses are based on single dosing because it is hard to recruit chronic pain patients to study their pain
Also the conversion is not bidirectional
What makes morphine a convenient opioid?
Morphine syrup is not considered a CD in Singapore
What condition should be flagged out when considering morphine usage and why?
Kidney failure
The active morphine-6-glucuronide is renally eliminated
Comment on the half life of fentanyl
it is very short
What are the two possible fentanyl patchdosing conversions?
Durogesic PI says:
3.6mg PO morphine equivalent to 1mcg/hr fentanyl patch
NCCN guideline says:
2mg PO morphine equivalent to 1mcg/hr fentanyl patch
What are some patient counselling points for fentanyl patches?
- do not apply on broken skin
- avoid taking noontime walks (hot)
- try to be around people who can look out for you
- if you experience episodes of nodding off or slow breathing, take off the batch
Comment on the onset and time to steady state for fentanyl? How does this influence dosing?
onset is slow (abt 6-8h before any effect)
time to steady state is long (2-3 days for full effect)
therefore usually dosed q72h
Which patient group is methadone usually reserved for
overdose patients or drug addicts
What effect does methadone have (MOA) that makes it unique?
μ-agonist
also has effects on NMDA
Comment on the half life of methadone and the risks associated with it
Very long, therefore risk of accumulation
Where is ketamine usually used in hospitals? Where else is it used in pain management?
in the operating room as an anesthetic
may be useful for opioid hyperalgesia (paradoxical reaction where patients become more sensitive to pain)
What should be taken note of with regards to other drugs when using ketamine?
Ketamine can potentially lower opioid tolerance
Because it can interact with other opioids and make them supercharged, baseline opioid doses must be drastically decreased (by 50% or more)
What are the prominent side effects of ketamine?
nightmares, insomnia
Briefly describe opioid tolerance
experience of reduced response to medication
requiring more opioids to experience the same effect
Briefly describe opioid dependence
body adjusts normal functioning around regular opioid use
unpleasant physical symptoms occur when the medication is stopped
Briefly describe opioid addiction or opioid use disorder (OUD)
attempts to cut down or control use are unsuccessful or when use results in social problems and a failure to fulfil obligations at work, school or home
What are the three main areas where the CDC Clinical Practice Guidelines for Prescribing Opioids for Pain are not applicable to?
- pain related to sickle cell disease
- cancer-related pain
- palliative care of end-of-life care
What are guidelines 1 and 2 (on non-opioids)
- Non-opioid therapies are at least as effective as opioids for many common types of acute pain
- Non-opioid therapies are preferred for subacute and chronic pain
What are guidelines 3 to 6 (initiating, dosage, changing, quantity)
- When initiating, prescribe immediate-release opioids
- Prescribe at the lowest effective dosage and avoid increasing dosage above levels likely to yield diminishing returns in benefits relative to risks
- Exercise care when changing opioid dosage
- Optimise non-opioid therapy while continuing opioid therapy
- If benefits do not outweigh risks, gradually taper
- Prescribe no greater than the quantity needed
What are guidelines 7 to 12 (evaluation, evaluation, monitoring, testing, DDI, OUD)
- Evaluate benefits and risks early and regularly
- Evaluate and discuss opioid-related harms and mitigation steps if needed
- Drug-monitoring program (PDMP)
- Consider the risks and benefits of toxicology testing
- Exercise caution when combining opioids with benzodiazepines and other CNS depressants
- Use evidence based medicine to treat OUD
What are some possible adjuvants to pain management? (5)
GABA-acting anticonvulsants (pregabalin, gabapentin)
SNRIs, tramadol, lidocaine patches
What effect does tramadol have?
μ-agonist and a serotonin reuptake inhibitor
some combined effect for neuropathic pain
What are the three main end-of-life syndromes
dysnpea
secretions
agitation and delirium
What is the main treatment considered for dyspnea? In what cases should it not be used and why?
Non-pharm: oxygen therapy
CI with previous bleomycin chemotherapy (increases risk of pulmonary toxicity)
What are the two main treatment considered for secretions (drooling)?
Glycopyrrolate (exempt)
Anticholinergics (if already indicated)
When are antipsychotics considered for agitation and delirium?
last resort, for underlying condition
atypical antipsychotics like quetiapine are better
What causes should be taken note of when handling agitation and delirium?
medication related causes
find alternatives or consider deprescribing
How can bowel obstructions be dealt with?
Pancreatic enzymes (crushed) to unclog tubes
What are 5 other less common end-of-life syndromes?
anorexia/cachexia
persistent nausea
chronic diarrhea/constipation
insomnia/over-sedation
wound care or pressure ulcers
