Pain in Palliative Care: Tx Flashcards
(35 cards)
Management of Pain
By the ladder
By the mouth
By the clock
With breakthrough dosing
Individualized for patient
Address all aspects of suffering
Monitor efficacy regularly
Identify and treat underlying causes (if feasible)
Classification of Pain
Using numerical
rating scale (1-10)
(from ESAS-r)
◦ Mild pain (1-3)
◦ Moderate pain (4-6)
◦ Severe pain: 7-10
WHO analgesic ladder
WHO Ladder for Pain Control
Step 1
Mild Pain
Step 2
Moderate Pain
Step 3
Severe Pain
Non-opioids
Acetaminophen
NSAIDS
+/- Adjuvants
Weak opioids
Codeine
Tramadol
+/- Adjuvants
Strong opioids
Morphine
Hydromorphone
◦ Laxatives should be prescribed in most cases (opioids)
◦ Insufficient evidence to support/refute Step 2
opioids (eg. codeine) are superior to NSAIDS
◦ In rapidly progressing pain Step 2 may be omitted
Use low doses of Step 3 analgesics (eg. morphine)
Need to adjust dosing
◦ Geriatrics, and those with decreased cognitive or
organ function.
◦ Opioid tolerant or history of opioid misuse
Oral route is preferred
◦ Easier to administer
◦ Cheaper
◦ No special techniques
required
◦ No specialized pharmacy
◦ No risk of infection
◦ Less painful
May not be possible if:
◦ Malabsorption from gut
Short gut, bowel obstruction
Nausea/vomiting
◦ Patient delirious/unresponsive
By the clock
Continuous pain
or pain which
occurs
frequently,
requires around
the clock
analgesia
Breakthrough Pain
In addition to regular pain most patients
experience pain flares: breakthrough pain
Need prn order in addition to ATC orders
Usually: 10% of daily dose q1h prn
May be associated with a particular activity
◦ Incident pain
Take prn dose before doing that activity
Or daily variation of the pain
◦ Dose when pain increases
if exceed max, neeed reassessment
All Aspects of Suffering
Identify & Treat Underlying
Causes
Address the
physical,
psychological,
spiritual and
social problems
the patient may
be experiencing
If appropriate
◦ Tumors
Palliative
chemotherapy
Palliative
radiation
Palliative surgery
◦Infections
Antibiotics
◦ Constipation
Laxatives
Step 1: Acetaminophen
Used as mild analgesic and adjuvant
Maximum dose (from all sources)
◦ 4000mg/day
Should only be short-term in healthy adults
◦ 3000 mg/day
Long term use in healthy adults (≥ 7 days)
◦ 2000mg /day or avoid
Heavy alcohol use, malnutrition, low body weight,
advanced age, febrile illness, advanced liver disease,
interacting medications
Dose restrictions may limit efficacy
Step 1: NSAIDS
Have traditionally be used for mild cancer pain
Mild analgesic and adjuvant
As effective as weak opioids
Effect in bone pain not as robust as previously
thought: may have benefit in select cases
Adverse effects limit their use particularly in
elderly/frail population.
◦ GI, kidneys, increased bleed risk
Ibuprofen, naproxen, diclofenac (honestly rarely used)
◦ Topical diclofenac is used
Patient Concerns with Opioids
Only used at end of life. With increased survivorship
patients may take these agents for months or years.
Not shown to shorten life when used appropriately.
Very sedating (can’t drive): patients usually
overcome sedation after a few days.
Addiction: Majority of patients do not become
addicted. Dose increases over time may be due to
tolerance. Monitor closely.
If started too early there will be no no options at
the end. Pain does not necessarily increase at the
end of life. Doses can be increased or switch agents
Start Low & Go Slow
When initiating opioids start at lower doses
Dose reduce in presence of frailty or organ
dysfunction
Up-titrate slowly to effect
Monitor for adverse events
◦ Prescribe laxatives to prevent constipation
Naloxone kit (call ambulance)
◦ Patient may have pain crisis if used (immediate)
- controversy for palliative pop, have it for ppl in the house who make help take their opioids for them
Step 2: Codeine
Exhibit a ceiling effect: Maximum effect
Naturally occurring opioid.
~ 1/10 as potent as morphine
Metabolized to morphine
◦ Via CYP 2D6
Genetic polymorphism may alter metabolism
Drug interactions
Dose
◦ Start 8-15 mg
◦ Maximum: 300 to 400 mg
Single agent or combination
Long-acting forms available
Step 2: Tramadol
Weak opioid & inhibitor of norepinephrine &
serotonin reuptake
Liver metabolized
Dose: 50 to 100 mg every 6 hrs
Maximum dose= 400 to 600mg daily
Adverse effects ;
◦ Nausea & dizziness are transient
Care with seizure disorders, raised ICP, hepatic and
renal impairment
Care TCA’s & SSRI’s (lower seizure threshold)
Long-acting formulations available
Not covered by many drug plans
Strong
Opioid Suggested starting dose
Morphine 5 to 10 mg PO q4h atc
Hydromorphone 1 to 2 mg po q4h atc
Oxycodone 2.5 to 5 mg po q4h atc
Fentanyl 25 mcg/h (Do not use 1st –line)
Methadone Dose varies (Do not use 1st line)
Consider dose reductions in the elderly/frail, opioid-naïve patient
Adverse Effects of Opioid
Early/Acute
◦ Usually resolve
Nausea
Sedation
Respiratory depression
Pruritus
Urinary symptoms
◦ Except
Constipation
Late/Chronic
◦ Constipation
◦ Hypogonadism
◦ Neurotoxicity
◦ Tolerance
◦ Addiction
◦ Withdrawal
Fentanyl
Potent (100 x stronger than morphine)
Not active orally
◦ Transdermal patches
◦ Injectable
Intermittent: Incident pain
Rapid onset, short acting
Use 15 minutes prior to aggravating activity
Continuous infusion (subcut or IV)
◦ Sublingual - but very expensive
◦ Intranasal (no commercial product available)
Do not use if opioid-naïve
Not covered by many drug plans
Conversion to Fentanyl Patch
Morphine oral dose
mg/24 hrs
TD Fentanyl
mcg/hr q72h
45-134 25
135-224 50
225-314 75
315-404 100
405-494 125
495-584 150
585-674 175
675-764 200\
12 h to stady state, need to bridge so they dont have pain
Sublingual Fentanyl
Sublingual tablets
◦ Abstral
Buccal tablets
◦ Fentora
Expensive
◦ Not covered by 3rd
parties
◦ Hospital formulary
Compounding
pharmacies
Can use the
injectable
sublingually
50 mcg/mL
Measure dose in
syringe & hold under
the tongue as long
as possible
dosed q8h for the patient
no adjustment for renal failure
methadone as analgesic
Renewed interest
◦ Low cost
◦ Activity against
neuropathic pain
syndromes
◦ ↓ neurotoxicity
Receptors
◦ μ, k & δ (agonist)
◦ NMDA receptors
(antagonist)
◦ Norepinephrine &
serotonin reuptake
Metabolism
◦ CYP 3A4
Induced or inhibited
◦ CYP 1A2
Induced or inhibited
◦ CYP 2D6
Depends on
polymorphism
methadone drug interaction
↓ Methadone ◦ Antiretrovirals Nevirapine Ritonavir ◦ Phenytoin ◦ Carbamazepine ◦ Dexamethasone ◦ Rifampin ◦ Spironolactone ◦ Alcohol/tobacco
↑Methadone ◦ Cimetidine ◦ Omeprazole (not on hospital formulary(◦ Ketoconazole ◦ Fluconazole ◦ SSRI’s ◦ Verapamil ◦ Ciprofloxacin ◦ Macrolides
methadone and ATc interval
Prolongs QTc
interval
Dose related (300-
600mg/day)
Not usually a concern in
palliative patients
Cumulative with other
agents: avoid if possible
◦ Levofloxacin
◦ Fluconazole
◦ Arsenic
methadoe tx advantages
Advantages
◦ Potent and effective
analgesic
◦ Inexpensive
◦ Fewer neuro-toxicities
◦ Long T1/2 (fewer daily
doses)
Neuropathic pain
◦ NMDA receptors
◦ NOR & 5HT
Can be administered to
those highly tolerant to
other agents
Incomplete crosstolerance helps control
intractable pain
Tablets and syrup
commercially available
Methadone as a Co-analgesic
Using low dose methadone in addition to
regular opioid
Does not necessitate full methadone rotation
◦ No hospitalization, rapid initiation, less expertise
required.
Patient does not get the full benefit of
methadone - downside
Difficult to determine origins of toxicities with
more than opioid on board
Ppl unable to do complete methadone rotation
North America 3rd
or 4th line
Europe &
developing
countries often 2nd
line after
morphine
methadone disadvantages
◦ Kinetics unpredictable
Courses for prescribers
◦ Rectal & injectable
forms not
commercially available
Compounding
pharmacies
other receptors involved, not straight conversion
