Cancer Pain

What are the general principles of pain management in oncology patients?

• assess all patients for pain

• reassure patients and family caregivers that pain can be relieved

• prepare clinicians to assess and manage pain

• patient and family caregiver education

• collaborate

What are the sources of cancer pain?

• nociceptive (tissue damage, space occupying/mass lesion, inflammation)

• neuropathic (nervous system pathology, allodynia, hyperalgesia, residual from chemo/radiation)

What is constant pain in cancer patients?

continuous, persistent pain

What is incident pain in cancer patients?

brought about by a specific action or event, which may be voluntary (moving, walking, eating) or involuntary (cough, defecation)

What is breakthrough pain in cancer patients?

an unpredictable exacerbation of baseline pain

True or False: some suggest moving the second step in the pain ladder for cancer pain

true

What should the initial treatment be based on?

the severity of pain that the patient reports

What should the initial treatment be if the cancer pain is mild?

non-opioid analgesic

What should the initial treatment be if the cancer pain is moderate?

opioid

What should the initial treatment be if the cancer pain is severe (pain emergency)?

opioid

What is the best dosing interval for PRN analgesic medications?

q3h

What dosing interval is unacceptable for PRN analgesic medications?

q6h

What are the pros of opioids?

• no ceiling dose

• many routes for administration

What are the cons of opioids?

• toxicity

• side effects: GI, constipation, N/V, CNS, repsiratory depression, orthostasis, urinary incontinenece

• fears of addicition or dependence

What side effects of opioids need to be monitored for and prophylactically treated?

• constipation

• nausea/vomiting

• respiratory depression

• CNS depression

What is 1st line for management of opioid induced N/V?

metoclopramide

What medications can be used to manage opioid induced N/V?

metoclopramide, haloperidol, prochlorperazine, diphenhydramine, scopolamine, ondansetron, lorazepam, olanzapine

What is the mainstay of therapy for opioid induced GI effects?

stimulant laxatives (senna, bisacodyl)

What medications are opioid antagonists that are used for opioid induced constipation?

naloxegol, methylnaltrexone, naldemedine

What role do saline laxatives have in opioid induced constipation?

quick relief then adjust/obtain a maintenance regimen

What type of opioid regimen should a patient be on if they have constant pain?

long acting opioid on an around the clock basis long with an IR opioid to be used as needed

What is the brand name of morphine ER?

MS contin, Kadian, Avinza, Morphabond

What is the brand name of morphine + naltrexone?

Embeda

What is the brand name of oxycodone ER?

OxyContine, Xtampza ER, Oxaydo

What is the brand name of oxycodone ER + naloxone?

Targiniq

What is the brand name of hydrocodone ER?

Hysingla ER, Zohydro ER

What is the brand name of oxymorphone ER?

Opana ER

What is the brand name of tapentadol ER?

Nucynta ER

What is the brand name of hydromorphone ER?

Exalgo

What is the brand name of fentanyl transdermal?

Duragesic

What is the brand name of buprenorphine (transdermal)?

Butrans

What is the brand name of methadone?

dolophine, methadose

How much should PRN dosing be when the patient is already on around the clock/long acting opioid?

10-20%

What are the advantages of methadone?

• pain relief in patients unresponsive to current opioid treatment

• diminished incidence of side effects 

• multiple routes of administration

What is the MOA of methadone?

mu agonist, delta agonist, NMDA receptor antagonist, NE and 5HT reuptake inhibition

What is the dosing for methadone oral tablets?

5mg, 10mg, 40 mg (dispersible tab)

What medication is the only opioid available as a long-acting liquid?

methadone

What dosages are available for methadone solution?

5mg/5mL, 10mg/mL, 10 mg/mL

What is the dose of methadone IM injection?

10mg/mL

What is the absorption of methadone?

80% bioavailable and 15-45min onset

True or False: methadone has a small volume of distribution

false

What is the volume of distribution of methadone

very large

Why is the volume of distribution of methadone so large?

it is lipophilic and accumulates in the tissue; binds alpha-1 acid glycoprotein

What is the time range to steady state of methadone?

70.5 hours - 233.5 hrs. (3-10 days)

What is the duration of action of methadone?

6-8 hours with single dose

8-48 hours with chronic dosing

What is the metabolism and elimination of methadone?

metabolized to inactive metabolites; CYP3A4 substrate; mostly fecally eliminated, minor renal excretion

What is the range of ratio of morphine: methadone?

3:1 - 20:1

What is the dosing of methadone in a opioid naive patient?

2.5mg 2-3x/day (± PRN)

What is the dosing of methadone in an opioid conversion patient?

5-10mg 2-3x/day

What is 1st line for bone pain?

steroids or anti-inflammatory doses of NSAIDs

What is 2nd line for bone pain?

add pamidronate, zoledronic acid or other bisphosphonates

What is 3rd line for bone pain?

strontium89, radiotherapy

What is 4th line for bone pain?

surgical interventions

What are considered the backbone of bone pain in metastatic disease?

corticosteroids and nonsteroidal anti-inflammatory drugs

What doses of corticosteroids should be used for bone pain?

up to 30-100mg dexamethasone daily; stary 8-16mg/day

What are the side effects of corticosteroids?

appetite stimulation, psychosis, insomnia, nausea

True or False: you should consider the long-term side effects of high dose anti-inflammatories?

true

What are examples of adjunctive agents (co-analgesics) for cancer pain?

• gabapentinoids

• TCAs

• SNRIs

• anticonvulsants

• opioids 

• BZDs

True or False: co-analgesics/adjunctive agents can be used 1st line in cancer pain for neuropathy

true

What opioids are available as a liquid?

• morphine

• methadone

• hydromorphone

• oxycodone

What is tolerance?

physiologic adaptation to the continual presence of a drug resulting in higher doses needed to achieve the same effects

What is phsyical dependece?

occurrence of an abstinence syndrome upon dose reduction, D/C or antagonist administration

What is addiction?

characterized by behaviors that induce impaired control over drug use, compulsive use, continued use despite harm, and craving

What is pseudoaddiction?

distress and drug-seeking behaviors that occur in the context of unrelieved pain; these behaviors subside when analgesia is achieved