Lec 4: Cancer Pain Management Flashcards
Acute Pain - General
- Normal predicted physiological response to an adverse stimulus
- Result of activation of the pain receptors (nociceptors) at the site of tissue damage.
- Warning signal that something is wrong
- Self-limiting and usually resolves over days to weeks
- Activates sympathetic branch of the autonomic nervous system to produce hypertension, tachycardia, diaphoresis, shallow respiration, restlessness, facial grimacing, guarding behavior, pallor, and/or pupil dilation
- Can be associated with significant physical, psychological, and emotional distress
- Inadequately controlled pain can be a factor in the development of chronic pain
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NOTE: Pain include many dif aspects: physical, emotional, social, adn spiritual
Chronic Pain - General
- Intractable pain that exits for 3 or more months and does not resolve in response to
treatment. - Can be viewed as its own disease
- Can be affected by physical, environmental, and psychological factors
- May reduce quality of life, well-being, and ability to function over the long-term
- Positive adaptation does not occur
- Does not resolve on its own
Classification of Pain
Nociceptive pain (maintained by continual tissue injury) : Somatic pain
SOMATIC PAIN
- Tissue damage to skin, soft tissue, muscle or bone
- Descriptors: aching, gnawing, deep, dull, sharp, stabbing
- Well localized – patients can often point with one finger to the location of their pain
Classification of Pain
Nociceptive pain (maintained by continual tissue injury) : Visceral pain
Classification of Pain
Non-nociceptive pain: Neuropathic pain
- Injury or inflammation of nerves. Often coexists with somatic or visceral pain
- Descriptors: burning, electric, numb, radiating, lancing, shooting, tingling
- Radicular: single or multiple nerve roots,
Herpes zoster, sciatica - Stocking-glove: Fingers and toes
- Diabetic or chemotherapy-induced neuropathy
Classification of Pain
Cancer-related bone pain
- Somatic nociceptive and neuropathic
components - Deep, aching, localized
- Intensifies with movement and/or weight
bearing - Activation of osteoclasts and osteolysis leads
to pain and hypersensitivity in the bone and
periosteum - Cancer within bone marrow causes neuropathic pain and neuroplastic response
- Nerve growth factor is released causing
central sensitization
Pain Assessment Part 1: important acronym to access?
P = palliating/provoking
Q = quality
R = region/radiation
S = severity
T = timing (onset, duration, frequency)
U = YOU (goals, activity level, QOL)
Pain Assessment Part 2: Additional questions
Quality:
- What does your pain feel like?
- What words would you use to describe your pain?
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Region and Radiation:
- Where is your pain?
- Where does the pain start?
- Does the pain move anywhere?
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Aggravating/Alleviating Factors:
- What makes your pain worse? better?
- What previous treatment have you tried to relieve your pain?
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Intensity:
- On a scale of 0 to 10, with O being no pain and 10 being the worst pain you can imagine, how much does it hurt right now?
- How does the pain compare with other pain you have experienced?
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Temporal Characteristics:
- When did your pain start? How often does it occur?
- How long does it last?
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Functional Impact:
- How does the pain affect your sleep? Your appetite? Your energy level?
- How does the pain affect your mood? relationships?
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NOTE: use Wong Baker faces to rate pain or numerical rating 0-10
When are Opioids Indicated? What are the general steps/ ladder?
When are Opioids Indicated?
- Moderate to severe pain related to cancer or active cancer treatment
- In a 2016 review of oral morphine, the study indicated that 96% of morphine-treated patients achieved the outcome of no worse than mild pain
- Clinicians should discuss goals regarding functional outcomes, shared expectations, and pain intensity, as well as any concerns about opioids (eg. addiction ? use lowest dose?)
- Opioids should be initiated as immediate release and PRN (as needed) to establish an effective dose, with early assessment and frequent titration
Fentanyl : importance
- Transdermal, transmucosal, and parenteral formulations
- May only be used in patients receiving at least 60mg oral morphine, 30mg oral oxycodone, 8mg oral hydromorphone, or equivalent daily for at least one week (no need to know specific dose, but know TDF should NOT be used for opiate naïve patients!)
Methadone: Importance
- Poorly predictable potency with switch from
another opiate - May reverse a component of opioid analgesic tolerance
- Half life can vary from 12 hours to 7 days,
average is 24 hours and can lead to accumulation - Multiple drug-drug interaction due to
metabolism by cytochrome P450 system - 80% oral bioavailability
- QTc prolongation
Cardiac Concerns with Methadone?
- Methadone Should Be Use with caution with other meds that prolong QT interval
—– Antipsychotics (chlorpromazine, haloperidol)
—– Antidepressants (citalopram, escitalopram)
—— Antibiotics (quinolones, macrolides)
—— Antiemetics (prochlorperazine, ondansetron) - Low potassium and/or magnesium can increase risk
Good/Bad Methadone Candidates
Potential Drug Interactions with Methadone
Buprenorphine: what is it? / advantages?
What is it?
Mu-opioid partial agonist
— Parenteral for severe acute pain
— Sublingual as opioid agonist therapy
— Transdermal (Butrans®) and transmucosal (buccal film, Belbuca®) for chronic pain
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Advantages of buprenorphine include:
- Effectiveness in treating a variety of pain syndromes
- Less adverse effects (constipation, cognitive impairment, respiratory depression, immunosuppression, hypogonadism)
- Better safety profile in vulnerable populations (elderly, renal impairment)
- Fewer withdrawal symptoms