Pain Management Flashcards
Is cancer pain a manageable concern?
Yes, in most cases
What % of cancer pain can be relieved relatively simply, with oral analgesics and adjuvant drugs?
80-90%
What is the problem with inadequate pain control in cancer?
It may exacerbate other problems
What other problems might be exacerbated by inadequate pain control in cancer?
- Fatigue
- Nausea
- Constipation
- Depression
Why might pain affect compliance in cancer?
It is more difficult for a patient in pain to continue with demanding cytotoxic treatments and hospital visits
What should be done when a patient presents with cancer pain?
A careful history should be taken to identify any reversible or remediable causes of the patient’s pain
What might cancer pain derive from?
- Tumour progression and related pathology
- Procedural intervention
- Treatment toxicity
- Infection
- MSK issues
Specifically, what are the most common causes of pain in cancer patients?
- Peripheral neuropathies secondary to chemotherapy or tumour invasion
- Tissue injury secondary to radiotherapy
- Chronic post-surgical incisional pain
- Bone metastases
- Visceral pain
What can aggravate cancer pain?
- Other physical symptoms
- Psychological symptoms
- Social factors
- Spiritual or existential suffering
- Medical crisis
What other physical symptoms can exacerbate cancer pain?
- Insomnia
- Loss of appetite
- Fatigue
What psychological symptoms can exacerbate cancer pain?
- Distress
- Anxiety
- Depression
What happens even though cancer pain is manageable?
It is often undertreated
this card is bit dodgy sorry lol
What medical failures most commonly contribute to uncontrolled cancer pain?
- Inadequate assessment
- Failure to detect general distress
- Lack of systemic approach to analgesia
- Lack of knowledge of opioid pharmacology
How can inadequate assessment lead to uncontrolled cancer pain?
Can result in misdiagnosis of the cause and type of pain
How can failure to detect general distress lead to uncontrolled cancer pain?
Lowers pain threshold
??? lol
Give an example of when lack of knowledge of opiate prescribing can lead to uncontrolled cancer pain
Failure to anticipate and prevent side effects
Why is it important to understand the patient’s pain in cancer
Because treatment must be tailored for the individual, according to the nature, likely mechanisms, and subjective component of pain
Is a diagnosis of cancer a sufficient explanation for the patient feeling pain?
No
What is the result of a diagnosis of cancer being an insufficient explanation for the patient experiencing pain?
You need to determine what is the actual cause
What might pain of a sudden onset suggest in cancer?
- Acute complication of the malignancy
- Unrelated cause, e.g. new pathological fracture, mucositis due to radiotherapy
What might chronic escalating pain be caused by in cancer?
Underlying disease progression, e.g. soft tissue or nerve root infiltration
What are the different natures of pain?
- Somatic
- Visceral
- Neuropathic
What are the characteristics of somatic pain?
Typically localised and persistent
Give 2 examples of causes of somatic pain in cancer
- Bone metastases
- Localised inflammation such as cellulitis
What are the characteristics of visceral pain?
Usually poorly localised, of variable intensity, and often occurring with associated symptoms such as nausea
Give 2 examples of causes of visceral pain in cancer
- Hepatic metastases
- Malignant abdominal lymphadenopathy
What are the characteristics of neuropathic pain?
- Classically described as ‘shooting pain’ or ‘burning’
- Usually follows a nerve distribution
- Typically less responsive to opiate therapy
Give an example of a cause of neuropathic pain in cancer
Compression of spinal nerve root
What is the result of pain having a strong affective component?
It is greatly influenced by mood and morale
Why is it important to consider the affective component of pain when managing it?
An understanding of the patient’s perception of pain will help formulate an effective management plan
What psychological aspects should be addressed when managing pain?
- Anger
- Fear
- Distress
What is the result of managing anger, fear, and distress when managing cancer pain?
It will increase the likelihood of achieving satisfactory pain control
What does the approach to cancer pain management entail?
A foundation of pharmacologic management, which is tailored with individualised care
What does pharmacological pain management follow in cancer pain?
The WHO analgesic ladder
What is step 1 in the WHO analgesic ladder?
The initial treatment of mild to moderate pain with non-opioid analgesia
What analgesics might be used in step 1 of the WHO analgesic ladder?
- Paracetamol
- NSAIDs
- Combination of paracetamol and NSAIDs
- Cox-2 inhibitors
What is paracetamol?
Analgesic and anti-pyretic
Does paracetamol have anti-inflammatory action?
No
Are adverse reactions common with paracetamol?
Rare at prescribed doses
Give 3 examples of NSAIDs used in step 1 of WHO analgesic ladder
- Ibuprofen
- Naproxen
What should you be aware of when prescribing NSAIDs?
Issues regarding gastric protection and renal function
Give an example of a cox-2 inhibitor
Celecoxib
What is the action of celecoxib?
Anti-inflammatory
What is the advantage of celecoxib over NSAIDs?
May result in lower incidence of gastric irritation and renal toxicity
What is the disadvantage of celecoxib?
Associated with increased risk of MI and stroke
What can non-opioid analgesics be paired with?
Adjuvants
Give 3 adjuvants that can be paired with non-opioid analgesics
- Agents for neuropathic pain
- Bisphosphonates for bone pain
- Corticosteroids for bone pain
Give 3 examples of agents for neuropathic pain
- Gabapentin
- Duloxetine
- Amitriptyline
Where are bisphosphonates a useful adjunct?
Particularly in breast cancer and multiple myeloma, but also in lung, GI, and prostate cancer
Give 3 examples of corticosteroids used as a pain adjunct
- Prednisolone
- Dexamethasone
What is step 2 in the WHO analgesic ladder?
Treatment of mild to moderate pain that is not responsive to step 1 therapy, or for the initial treatment of severe pain
What does step 2 in the WHO analgesic ladder involve?
Low doses of opioid analgesia
What drugs may be used in step 2 of the WHO analgesic ladder?
- Codeine phosphate
- Low dose morphine, or similar dose of oxycodone
What dose of codeine phosphate is given in step 2?
30-50mg tds
What is the problem with codeine phosphate?
It can cause substantial nausea and vomiting in many patients
What should be done as a result of the potential for codeine phosphate to cause substantial nausea and vomiting?
Consider adding anti-emetic when prescribing
What dose of morphine is used in step 2?
<40mg total daily dose
Should the patient continue their regular non-opioid analgesics in step 2?
Yes, continue alongside the opioids
What can step 2 agents be combined with?
Adjuvants
What is the purpose of combining step 2 agents with adjuvants in pain management?
To tailor the pain management plan to the patients needs
What are the possible side effects of opioid analgesia?
- Nausea
- Constipation
In what manner should the side effects of opioid analgesia be managed?
Preventatively
What does step 3 in the WHO analgesic ladder involve?
More potent doses of opioid analgesia
What opioid analgesics are generally used for cancer pain?
- Morphine
- Oxycodone
- Fentanyl
- Hydromorphone
- Methadone
What do morphine metabolites do in the body?
Contribute to side effects
What side effects do morphine metabolites contribute to?
- Nausea
- Myoclonus
- Sedation
What can happen to morphine metabolites in the body?
They can accumulate
When are morphine metabolites particularly likely to accumulate?
In patients with liver or renal dysfunction
What opioids don’t have the same metabolites as morphine?
- Oxycodone
- Fentayl
- Hydromorphone
What is the result of oxycodone, fentanyl, and hydromorphine having different metabolites to morphine?
They may have few side effects
What are the additional benefits of metadone?
- May be prescribed for neuropathic pain
- Very inexpensive
What is the disadvantage of methadone?
Unpredictable half life
What is the result of methadone having an unpredictable half life?
Should be prescribed by experienced clinicians only
What opiate regime should be used in step 3?
Sustained release product, combined with immediate-release formulation for breakthrough pain and inadequate analgesia
What initial opiate dose should be used in step 3?
Start at 40-80mg OME/day
When should the starting opiate dose be reduced in step 3?
- Elderly patients
- Patients with liver or renal dysfunction
By how much should the starting opiate dose be reduced to in elderly patients/patients with liver or renal dysfunction?
50-75%
What should you do when you have established the starting dose of opiates in step 3?
Titrate the drug to the desired analgesic effect and tolerable side effects
What are the main side effects of opiates?
- Nausea
- Constipation
- Dry mouth
- Hallucinations
- Respiratory depression
How is nausea caused by opiates prevented?
Prescribe an anti-emetic
Give an example of an anti-emetic that can be prescribed to prevent nausea with opiates
Metaclopramide
What dose of metaclopramide is given to prevent nausea with opiates?
5-10mg every 6 hours as needed
How is constipation caused by opiates prevented?
Co-prescribe a laxative plus stool softener
How is dry mouth caused by opiates prevented?
- Access to fluids
- Mouth care
How are hallucinations caused by opiates treated?
Haloperidol 1.5-3mg as needed
Is respiratory depression caused by opiates common?
No, it is rare in cancer patients
When is respiratory depression caused by opiates seen?
Usually only at doses above those required for analgesia, or if the drug is accumulating
Give an example of when opiates may accumulate
Renal impairment
How is respiratory depression caused by opiate toxicity managed?
Naloxone
What does breakthrough pain refer to?
Intemittent flares of pain that occur even though the patient is properly taking around-the-clock analgesics, and pain is generally well managed
What proportion of cancer patients will experience breakthrough pain?
1/2 to 2/3
How should breakthrough cancer pain be managed?
Alongside each long-acting sustained release opioid, you should prescribe an immediate-release opioid
What dose of immediate-release opioid should be given for breakthrough pain?
Approx 10% of the long acting dose
What should the dose of immediate-release opioid for breakthrough cancer pain be adjusted for?
Efficacy vs side effects based on the patients report of symptoms
When giving opioids, what should be anticipated over time?
A slow increase in opiate requirements
Why should you except a slow increase in opiate requirement over time?
Opioid responsiveness falls along a continuum
Add in card about how to titrate opiate dose
cant remember if you divide by 2 or 4 lol
spare in case you need it
jj
What might limit the titration of opioids?
Unacceptable side effects, e.g. sedation
What should be done when the titration of opioids is limited by unacceptable side effects?
Adjuvant analgesics should be used
What should be considered when the patient has persistent pain despite appropriate use of analgesics?
If the patient has developed;
- Progressive disease
- Tolerance
- Withdrawal
- Hyperalgesia
What is the most common cause of pain that is suddenly difficult to control in cancer patients?
Progressive disease
What does tolerance to opiates lead to?
Increasing doses of analgesics being required to maintain the same level of pain control
Is tolerance to opiates common in cancer patients?
No, it is rare
What does tolerance to opiates usually respond to? W
- Increase in opiate dose
- Switching to different opioid
What causes opiate withdrawal in cancer patients?
Decreasing or stopping an opioid
What can opiate withdrawal cause?
Worsening pain
How can pain caused by opiate withdrawal be managed?
Adding back the opioid, or increasing opioid dose
What is opioid-induced hyperalgesia?
When opioids lead to increasing pain as the opioid is increased
When should referral to a pain specialist be considered?
If standard adjustments to the patient’s analgesic regime do not lead to improved pain control
What are many patients and families concerned about with opiates?
The possibility of addiction to strong opiates
What kinds of dependance can develop with opiates?
- Physical
- Psychological
- Due to habituation
What should patients be reassured of regarding addiction to opiates?
When properly managed, addiction is not an issue, and the risk of addiction in cancer patients is about 1 in 1000
