Pain 2 - Oops, All Opioids Flashcards
1
Q
What are the 3 main opioid receptor subtypes? What does activation of each do?
A
- mu (µ):
- Analgesia, euphoria, physical dependence, respiratory depression, reduced GI motility ( –> constipation), sedation - delta (ẟ):
- Analgesia, euphoria, physical dependence - kappa (ϰ):
- Analgesia, sedation, ? mood, does NOT contribute to physical dependence
2
Q
What are the “big 5” opioids?
A
- Morphine
- Codeine
- Hydromorphone
- Oxycodone
- Fentanyl
2
Q
What is the MOA of opioids?
A
Opioid molecules bind to opioid receptors in the central and peripheral nervous system, suppressing neuronal firing from the presynaptic neuron and also inhibition of postsynaptic nerves in some areas, which ultimately alters the transmission and perception of pain
3
Q
Opioid use in acute pain:
What is the usual oral starting dose and frequency of codeine IR? (tylenol + codeine + caffeine)
A
15-30mg q4h prn
4
Q
Opioid use in acute pain:
What is the usual oral starting dose and frequency of hydromorphone IR?
A
1-2mg q4-6h prn
4
Q
Opioid use in acute pain:
What is the usual oral starting dose and frequency of morphine IR?
A
5-10mg q4h prn
5
Q
What should we be taking into consideration when using opioids in acute pain? (3)
A
- Lowest dose (should not need >50 MEQ), shortest duration
- Use clinical judgement re: quantity (consider limit to 3-5 days to start)
- Education about adverse effects including toxicity, take home naloxone
6
Q
What are 3 advantages of opioid use in chronic non-cancer pain? (3)
A
- Potent analgesic effect
- Fast onset
- Relatively low risk of major organ toxicity
- Renal, hepatic, cardiac
7
Q
What are the adverse effects of opioid use in chronic non-cancer pain? (7)
A
- CNS depression
- Falls/fractures
- Constipation
- Apnea
- Hypogonadism
- Opioid-induced hyperalgesia
- Dependence, opioid use disorder
8
Q
What are some disadvantages (4) to opioid use in chronic non-cancer pain?
A
- Adverse effects (discussed in another card)
- Risk of diversion
- Tolerance –> withdrawal-mediated pain, escalating dose
- Long term evidence of benefit (>3 months) lacking
9
Q
Opioid use in osteoarthritis, chronic low back pain, and neuropathic pain. Yay or nay?
A
Nay. Only unless exhausted all other possible options
10
Q
When are oral IR opioids used?
A
Used for acute pain, breakthrough pain, or when initiating someone on chronic therapy
11
Q
What are the non-oral opioid formulations available? (4)
A
- Buccal/sublingual
- Suppository
- Transdermal
- Injection
12
Q
What is the initial dosing for controlled-/extended-release morphine tabs?
How about caps? (both 12h and 24h)
A
Tab: 10-15mg q12h
Cap (12h): 10mg q12h
Cap (24h): 10mg q24h
13
Q
What is the inital dosing for oral IR morphine? What is the maximum?
A
5-10mg q4h prn, maximum 40mg/day
14
Q
What is the mimumum time interval for dose increase of CR/ER morphine?
How about for IR morphine?
A
CR/ER: Minimum 2 days. Recommended 14 days
IR: 7 days
15
Q
Which two opioids are “opiates”?
A
Morphine and codeine
16
Q
Morphine is metabolized into two primary compounds (excreted in urine). What are they?
A
- Morphine-6-glucuronide
- Active analgesic - Morphine-3-glucuronide
- Not active as an analgesic, CNS stimulation
17
Q
Morphine use should be monitored closely (or avoided) if CrCl <__-__mL/min
A
20-30
18
Q
Morphine is the “reference” opioid. Meaning?
A
Use for conversion factor calculations
19
Q
The MEQ of codeine is?
A
0.15
20
Q
Codeine is a _______. Converted to morphine in the body via CYP___
A
prodrug; 2D6
21
Q
What are 2 CIs for codeine?
A
- ≤12 years old
- ≤ 18 years old post op tonsillectomy and/or adenoidectomy
22
Q
Codeine antitussive dose is?
A
≥15mg q4-6h
23
What is the initial dose of codeine CR?
50mg q12h
24
What is the initial dose of codeine IR?
15-30mg q4h prn
25
What is the minimum time interval for increasing a dose in:
Codeine CR
Codeine IR
AND, what is the suggested dose increase?
CR: 2 days - 50mg/day increase
IR: 7 days - 15-30mg/day increase
26
What is the maximum dose/day of codeine CR?
IR?
CR: 300mg q12h
IR: 600mg/day or acet 4g/d (since often in combo product)
27
MEQ of oxycodone is?
1.5 (meaning 1.5x more potent)
28
Oxycodone is metabolized by CYP___ and ___ to active metabolites
3A4 (major); 2D6 (minor)
29
What is the initial dose of oxycodone CR?
10mg q12h
30
What is the inital dose of oxycodone IR? What is the maximum?
5-10mg q6h prn, maximum 30mg/day
31
What is the minimum time interval for increase of oxycodone CR?
IR?
AND, what is the suggested dose increase?
CR: Minimum 2 days. Recommended 14 days - 10mg/day increase
IR: 7 days - 5mg/day increase
32
Hydromorphone MEQ is?
5 (5x more potent than morphine)
33
Hydromorphone is a good option if someone requires an opioid in _____ __________
renal impairment
34
What is the inital dose of hydromorphone CR?
PR?
Should know the max/day for them too.
CR: 3mg q12h. Max 9mg/day
PR: 4mg q24h. Max 8mg/day
35
What is the initial dose of hydromorphone IR? What is the maximum?
1-2mg q4-6h prn. Maximum 8mg/day
36
What is the minimum time interval for increasing dose for hydromorphone?
CR
PR
IR
What is the suggested dose increase?
CR: Minimum 2 days - 3 mg/day increase
PR: Minimum 4 days. Recommended 14 days - 4 mg/day increase
IR: 7 days - 1-2mg/day increase
37
Tapentadol vs. Tramadol. Which is more potent?
Tapentadol (less potent than morphine though)
38
Fentanyl is much more potent than morphine --> ___x
100x
39
Fentanyl __mcg/hour patch ≅100mg of oral morphine
25
40
Fentanyl patch is a good option for what pts? (2)
- For those who cannot take oral medications and who are opioid-tolerant
- Option for pts with renal impairment since no known active metabolites
41
Fentanyl patch dosing schedule is Q__h
72
42
Fentanyl patch may not be suitable in the following conditions: (4)
1. Diaphoresis (too sweaty for patch to stick)
2. Morbid obesity
3. Ascites
4. Cachexia (wasting of the body)
43
What are some fentanyl patch counseling points we should touch on? (10)
1. Do not apply in front of children
2. Remove old patch before applying new patch
3. Apply to a clean, dry, non-hairy skin area on the chest, back, flank, or upper-arm
4. If required, clip hair as close as possible to the skin
- Do NOT shave the area
5. Avoid sensitive areas or areas of excessive movement
6. Do not use an external source of heat on top of the area while patch is on (e.g., heated blanket/pad)
7. When placing patch on skin, hold firmly for at least 30 seconds – if it falls off, discard it and use a new patch on a different site
- If gel from the patch contacts your skin (e.g., hands) during the application procedure, wash with water only and not soap, as soap will increase the absorption of the patch through the skin
8. Remove the patch after 3 days
9. New patch should be applied to a different place on the skin
10. When disposing, fold patch in half so sticky sides stick together and dispose in a child-proof container and return to pharmacy for disposal
44
What is the MOA of methadone (for pain)?
Potent mu opioid receptor agonist and an NMDA (N-methyl-D-aspartate) receptor antagonist
- NMDA mechanisms play a role in prevention of opioid tolerance, potentiation of analgesic effects and neuropathic pain treatment
45
The observed duration of methadone analgesia is _-__ hours. Usually dosed q_h for pain. Differs from once daily dosing for opiod use disorder
6-12; 8
46
Caution using methadone in: (3)
1. Severe hepatic failure
2. Hepatitis
3. Concurrent antiretroviral use
47
Why is methadone useful in renal impairment?
Because inactive metabolites are excreted in the urine and feces
48
What are 2 risks involved with methadone?
1. Risk of QTc prolongation
2. Increases risk of serotonin syndrome when combined with serotonergic drugs
49
What are 3 considerations when switching someone from morphine to methadone?
1. Conversion guides refer to the expected final stable methadone dose
2. Starting dose should be much lower as the first step of a gradual cross rotation or "start low, go slow" method of initiation, and gradually increased until better pain and function control is achieved
3. Extreme caution must be exercised (esp if on high dose of previous opioid)
50
Buprenorphine comes in what formulation?
What kind of pain is it used for?
What is the dosing schedule?
Patch form for persistent, moderate pain. Applied q7 days
51
True or False? Buprenorphine can be used in opioid naive patients
True - start with 5mcg/hr q7d. Can increase after 7 days.
Max 20mcg/day
52
What should be considered if wanting to switch from one opioid to buprenorphine?
Buprenorphine dose in BuTrans is relatively low (even at max of 20mcg/hr) so conversion from relatively low doses (<90 MEQ) of other opioids only
53
What is the MOA of buprenorphine? That is, what are the receptor interactions (2)? What are the benefits (3)?
1. Mu-partial agonist
2. Delta and kappa antagonist
Benefits:
3. Analgesia, decreased opioid-induced hyperalgesia and tolerance
4. Better safety profile
5. May cause less anxiety and depression
54
Buprenorphine has more consistent serum concentrations, can alleviate end-of-dose withdrawal, and flexibility in dosing schedules. Why? (3)
1. High affinity
2. Slow dissociation
3. Long elimination half-life
54
Buprenorphine is metabolized by CYP___
3A4
55
Buprenorphine in renal and hepatic dysfunction. Yay or nay?
1. Safe in decreased renal function
2. Relatively safe with hepatic dysfunction (may decrease dose if severe impairment)
56
What are 3 general opioid CIs?
1. Allergy (rare)
2. Co-administration of a drug capable of inducing drug-drug interaction
3. Active diversion of controlled substances
57
General adverse effects of opioids (even in the short-term) includes? (6)
1. Sedation
2. Respiratory depression
3. Constipation
4. Nausea
5. Miosis (pinpoint pupils)
6. Itching/rash (pseudoallergy)
58
Patients will develop tolerance to all adverse effects of opioids except: (2)
1. Constipation
2. Miosis (pinpoint pupils)
59
What are the more long-term adverse effects that can develop with opioid use? (6)
1. Hypogonadism
2. Sleep apnea
3. Opioid-induced hyperalgesia (sensitivity to pain)
4. Opioid tolerance
5. Opioid dependence, opioid use disorder
6. Risk of opioid toxicity (overdose) multifactorial
60
What are some serious drug interactions seen with opioids? (5)
1. CNS depressants
2. MAOIs
3. QT prolonging drugs
4. Serotonin syndrome
5. Carbamazepine and tramadol due to increased seizure risk
61
Explain how opioids can cause hypogonadism (2)
1. Opioids influence the HPA axis and HPG axis
2. Opioids interfere with the modulation of hormonal release, including:
- An increase in prolactin
- A decrease in LH, FSH, test, and estrogen
62
The collective effects of the hormonal changes seen in opioid use may lead to: (4)
1. Decreased libido and drive
2. Aggression
3. Amenorrhea or irregular menses
4. Galactorrhea
63
How does opioid sleep apnea differ from "normal" sleep apnea? (2)
1. Patients on long-term sustained-release opioids show a distinctive pattern of sleep-disoriented breathing called central sleep apnea that is different from the disturbances usually observed in people with obstructive sleep apnea
2. The oxygen desaturation is more severe and respiratory disturbances are long during NREM sleep
64
How might opioid-induced hyperalgesia be managed? (3)
1. Consider dose reduction (tapering)
2. Opioid rotation (account for cross-tolerance)
3. Rotation to buprenorphine or methadone
65
Risk of iatrogenic opioid use disorder may be associated with: (3)
1. History of substance use disorder (SUD)
2. Taking opioids for >90 days, or
3. Taking higher doses (>120 MED)
66
Using a POMI or a COMM screen a score of >_ or >_ is a positive screen for each test, respectively
POMI: >2
COMM: >9
67
What is the recommendation for pharmacological treatment of opioid use disorder? What is the quality of evidence and strength of recommendation?
Adults with opioid use disorder should be offered agonist treatment as the standard of care
Quality = high
Strength = strong
68
The MAXIMUM recommended starting dose when switching a patient from morphine to methadone is?
30mg/day
69
What are 6 things to do when considering an opioid trial?
1. Patient assessment
2. Discuss benefits and harms
3. Document realistic expectations
4. Determine what success looks like
5. Discuss exit strategy upfront
6. Gather commitment to structured monitoring and reassessment
70
What are the steps of conducting an opioid trial? (8)
1. Decide and document trial duration
2. Set and document functional goals
3. Choose opioid and optimal dose
4. Implement with safer opioid prescribing principles, universal precautions, counselling about adverse effects
5. Reassess and measure opioid effectiveness
6. Monitor for AEs, medical complications, adherence, and risks
7. End titration
8. Document the trial
71
Opioid trial step 1: Trial duration. What is a reasonable length?
Within 3-6 months
72
Opioid trial step 3: Choose opioid dose. What is the lowest starting dose for an opioid-naive patient?
What formulation (2)?
1. Lowest starting dose is 5-10 MEQ single dose or daily dosage of 20-30 MEQ/day
2. Use IR initially
3. Consider transdermal buprenorphine for those who can afford it
73
The objective of an opioid trial is?
To determine the optimal dose for the individual patient
74
What are 2 ways to determine optimal dose for individual patients doing an opioid trial?
1. Start with a low dose and increase the dose in small quantities
- Opioids produce a graded analgesic response
2. Slow titration
- Avoids unnecessarily high doses
- Reduces the risk of sedation and overdose and it ensures that dose increase does not exceed the pt's tolerance
75
What do the 2017 Canadian Opioid Guidelines say about choosing opioid dose in a patient starting an opioid trial? (4)
1. Ideally restrict to ≤ 50 MEQ/day (risks > benefits at higher doses)
2. Avoid higher than 90 MEQ/day
3. Harms (overdose/death) increase with doses ≥ 50-90 MEQ
4. Long-acting agents dosed on a scheduled basis considered most useful
76
When starting an opioid trial we should consider starting at lower doses for pts with the following factors: (8)
1. Increased age (half the dose)
2. Decreased weight
3. Sleep apnea
4. Impaired renal or hepatic function
5. Interacting drugs/concurrent CNS depressants
6. Pulmonary disease or conditions that cause decreased pulmonary drive
7. Seizures
8. Risk of developing GI obstruction
77
The optimal opioid dose is reached with a BALANCE of 3 factors. What are they?
1. Effectiveness:
- Improved function or at least 30% decrease in pain intensity
2. Plateauing
- Effectiveness plateaus: increasing the dose yields negligible benefits
3. AE's/Risks
- AE's and risks are manageable
78
What is the issue of using PRN opioids for breakthrough pain? (3)
What should be done instead?
1. Patients may rely on PRN opioids
2. Leads to dose escalation without documented benefit on pain and function
3. PRN use may result in cycling of "pain, pain-relief and subtle euphoria"
4. Better for pt to learn other coping strategies
79
Opioid trial step 4: Implement with boundaries, education, and universal precautions. Pt should be provided education about what 4 things?
1. Possible functional benefits (limited in most cases)
2. Adverse effects (common, increase over time)
3. Drug interactions (increase risk of toxicity, e.g., gabapentinoids)
4. Importance of active, self-management strategies +/- ongoing exploration of non-opioid pharmacotherapy
80
Opioid trial step 5: Reassess and measure effectiveness. Pts should follow up q2-4 weeks during trial. What is being reassessed during follow up? (3)
1. Repeat inital pain assessment questionnaires
2. Revisit co-created functional goals (SMART parameters)
3. Documentation
81
Opioid trial step 5: Reassess and measure effectiveness. What considerations should be made before dose exceeds 90-200 MEQ/day? (6)
1. Has the patient shown appropriate opioid effectiveness in response to the dose increases to date?
2. Is diagnosis(es) accurate?
3. Is opioid considered effective for the patient’s diagnosis(es)?
4. Is further investigation and/or consultation required?
5. Are non-opioid treatment options available?
6. Is there an inadequately treated mental health disorder?
82
Opioid trial step 6: Monitor ADE, medical complications, adherence to plan, and risks. What medical complications are possible? (3)
1. Neuroendocrine abnormalities and erectile dysfunction
2. Sleep apnea
3. Opioid-induced hyperalgesia
83
When monitoring patients with higher risks of opioid misuse. Extra precautions could include: (2)
1. Ask the pt to bring their medication for pill counts and to explain any discrepancies (i.e., random pill counts)
2. Using screening tools to check for aberrant drug-related behaviours (e.g., UDS)
84
If opioid use disorder is suspected, how might we tighten up boundaries? (4)
1. Limited quantities
2. Weekly dispensing intervals
3. Random UDS
4. Avoid dispensing excessive quantities of medications
85
Opioid trial step 7: End titration. Titration ends when either the "optimal" dose is attained, or if it is considered a failed trial.
What does ""optimal" dose attained" entail?
Balance of effectiveness, plateauing, adverse effects/risk
86
Opioid trial step 7: End titration. Titration ends when either the "optimal" dose is attained, or if it is considered a failed trial.
What does "failed trial" entail? (3)
1. The pt experiences insufficient analgesia after two or three dose increases and/or unacceptable adverse effects and/or medical complications and/or risk are too high
2. There are indications of aberrant use and/or OUD
3. Insufficient improvement in ability to function as per SMART goals
87
List some universal precautions in opioid prescribing and dispensing (7)
1. Complete OUD screening with Opioid Risk Tool
2. One opioid prescriber, one pharmacy
3. Urine drug screens (+ alcohol)
4. Limited quantities
5. Lock box at home
6. Random pill counts (during refills, office visits)
7. Treatment agreement
88
Consider tapering when opioids taken for > _ ____ at regular intervals
1 week
89
How long should additional opioids generally continue (tapering plan) in the following use cases:
Mild
Moderate
Severe
Long-term recovery
Mild = 1-2 days if at all
Moderate = 3-5 days
Severe = 7-14 days
Long-term = 14 days or more
90
What is the risk of opioid tapering in pregnancy?
Severe, acute opioid withdrawal has been associated with premature labor and spontaneous abortion
91
What are 4 precautions to opioid tapering?
1. Pregnancy
2. Unstable medical and psychiatric conditions can be worsened by anxiety associated with withdrawal
3. If OUD: may lead to accessing from unregulated sources
4. Approach will differ for long-term vs. short term use
- Goals may need to change with increased duration/dose
92
Early symptoms of opioid withdrawal may include? (7)
1. Anxiety/restlessness
2. Sweating
3. Rapid short respirations
4. Runny nose, tearing eyes
5. Dilated reactive pupils
6. Other: sympathetic/stimulation
7. Brief increase in pain (usually days but up to 2-4 weeks)
93
How long until opioid withdrawal symptoms occur in the following:
Early stage
Late stage
Prolonged symptoms
Early = hours to days
Late = days to weeks
Prolonged = weeks to ~6 months
94
Late symptoms of opioid withdrawal may include? (8)
1. Runny nose, tearing eyes
2. Rapid breathing, yawning
3. Tremor, diffuse muscle spasms, bone/joint aches
4. Pilo-erection
5. Nausea and vomiting; diarrhea; abdom pain
6. Dysphoria
7. Fever, chills
8. Increased WBCs (if sudden withdrawal)
95
Prolonged symptoms of opioid withdrawal may include? (6)
1. Irritability
2. Fatigue
3. Malaise
4. Psychological/wellbeing (dysphoria, coping, craving)
5. Bradycardia
6. Decreased body temp
96
What are 7 pharmacologic management options for opioid withdrawal? (OCNTDLNH)
1. Sweating
- Oxybutinin
2. Physical withdrawal (sweating, anxiety, insomnia, nausea)
- Clonidine
3. Insomnia
- Non-drug and sleep hygiene measures
- Trazodone
4. Nausea/Vomiting
- Dimenhydrinate
5. Bowel function (diarrhea)
- Loperamide
6. Aches/Pains/Myalgies
- NSAID, acet
7. Anxiety/Irritability/Cramps/Rhinorrhea/Insomnia
- Hydroxyzine
97
What are 8 indications to consider opioid tapering? (PRN HS OOU)
1. Pt requests
2. Resolution of underlying cause
3. No meaningful reduction in pain or improved function
4. Higher dose but no evidence of benefit
5. Side effects
6. Opioid misuse
7. Overdose or other serious event
8. Using other substances OR medical conditions
98
What are 6 potential benefits to tapering opioid?
1. Lower risk of toxicity/overdose
2. Less side effects and long-term complications
3. Mood and energy improve
4. Less perseveration on pain and opioid around-the-clock
5. May report improvements in mood and pain
- ↓ withdrawal-mediated pain
- ↓ hyperalgesia
- “reset pain threshold”
6. Cost-saving
99
What are 4 general considerations to make prior to opioid tapering?
1. Determine what goal is reasonable
- Dose reduction vs complete discontinuation
- Overall goal is to improve function, reduce pain intensity
2. Discuss that plan may be paused or reassessed if pain and/or function deteriorates or withdrawal symptoms persist
3. Avoid making arbitrary dosing endpoints
4. Understand that complete taper may take many months-years
100
What are some limitations to opioid tapering guidelines? (3)
1. Overall limited evidence available to guide the design of tapering regimens
2. No evidence to guide specifics of tapering regimens for chronic pain patients
- Must be individualized
3. Gaps in literature remain regarding:
- Tapering rate
- Medication choice
- Use of alpha-2 adrenergic agonists to manage withdrawal
101
Slow and gradual opioid taper should typically decrease dose x-xx% Q_-_ weeks
5-10; 2-4
102
Rapid opioid taper should typically decrease dose __-__% q_-_ days
10-20%; 1-3
103
As taper gets closer to finishing, the taper should ____ ____
slow down
104
A slow and gradual taper may be completed in x-y months
1-6
105
A rapid taper is often completed in x-y weeks
1-2
106
A rapid taper may be desirable for which pts? (3)
1. At very high risk of opioid harms
2. Highly motivated to ds/c their opioid quickly
3. On low doses of opioids, for shorter periods of time
107
What is the strategy of rotating/"switching" opioids when it comes to tapering?
1. Switch to alternate opioid at 50-75% of the current morphine equivalent dose (MED)
- 50-75% is an estimate
- When deciding empiric dose reduction also consider:
age, risk of adverse effects, comorbidities, duration of opioid therapy
108
What are the 4 advantages to rotating/"switching" opioids tapering approach?
1. Takes advantage of incomplete cross-tolerance between opioids
2. Gives a “head start” on the taper
3. Can facilitate switching to an opioid that is easier to taper
4. Can improve pain control +/- ↓ opioid related ADEs
109
Due to unpredictable and incomplete cross-tolerance from one opioid to another, suggested initial doses of the new opioid are as follows:
- If previous dose was high (≥ 200mg total daily oral MEQ) then SUGGESTED new opioid dose is?
50% or less of previous opioid (converted to morhine equivalent)
110
Due to unpredictable and incomplete cross-tolerance from one opioid to another, suggested initial doses of the new opioid are as follows:
- If previous dose was low (<200 total daily MEQ) then SUGGESTED new opioid dose is?
75% of the previous opioid (converted to morphine equivalent)
111
When trying opioid rotation as a tapering option, what should we consider when it comes to which opioid to use? (3)
1. Review comorbidities (e.g., renal and hepatic function) and medication history (e.g., drug interactions, intolerances, prior trials)
2. Look for an extended-release product the person is not currently taking/has not taken previously
3. Consider cost/coverage
112
What are the benefits of once daily opioid options? (5)
1. ↓ pill burden
2. ↑ adherence
3. Maintain therapeutic level through the day
4. ↓ psychological focus on opioids
5. ↓ chance of “borrowing” from tomorrow’s supply
113
Parenteral opioids (IM, IV, subcut) are ~_x as potent as oral
2
114
MEQ summary, but should really know these. To convert TO oral morphine equivalent, multiply the following by:
Morphine
Codeine
Oxycodone
Hydromorphone
1
0.15
1.5
5
115
What is cross-over rotation approach to opioid tapering?
Simultaneously decrease the dose of one opioid while up-titrating a new opioid
116
Why is cross-over rotation not preferred?
Conversely, what is a possible advantage?
1. Not preferred as it can be confusing and risks the patient having two opioids
2. Possible advantage is reducing risk of withdrawal symptoms during rotation to new opioid
117
Patient is on hydromorphone 10 mg po daily. What is their total daily morphine equivalent (MEQ)?
Hydromorphone MEQ = 5
Therefore, would multiply by 5.
10 x 5 = 50 MEQ
118
Patient with chronic back pain is taking T3 (300mg acet/30mg codeine/15mg caffeine) 3 tabs po q4h scheduled for chronic back pain. What is the pt's total daily MEQ?
First get total codeine dose.
3 tabs q4h means 30mg x 3 x 4 = 540mg
Codeine MEQ = 0.15, so 540 x 0.15 = 81 MEQ
119
Current inpatient medication administration record for Patient A:
Hydromorphone 1 mg subcut q4h scheduled.
What is Patient A's total daily MEQ?
Remeber, parenteral is 2x as potent than oral. So hydromorphone 1mg subcut = 2mg oral hydromorphone
2 mg oral q4h = 12 mg
Hydromorphone MEQ is 5
12 x 5 = 60 MEQ
120
Current inpatient medication administration record for Patient B:
Morphine 5mg IV intermittent q4h scheduled
Oxycodone 5mg po q4h prn - used 3x5mg doses in last 24 hours.
What is Patient B's total MEQ in the last 24 hours?
Remeber, parenteral is 2x potent than oral. So morphine 5mg IV = 10mg oral morphine
10mg oral q4h means 10mg x 6 doses = 60mg
Total oxycodone is 3x5mg = 15mg. Oxycodone MEQ = 1.5
15 x 1.5 = 22.5 mg morphine
Now add the two together:
MEQ = 60mg + 22.5mg = 82.5 MEQ
121
Patient C is taking M-Eslon SR 100mg po q12h
Patient C has declining renal function and her family physician is worried that the pt seems to be experiencing CNS AEs from morphine and would like to change to hydromorphone.
What dose of hydromorphone would you recommend?
Current MEQ = 100mg x 2 = 200mg/day
Hydromorphone MEQ is 5, but in this case going from morphine to hydromorphone so have to do 200/5 = 40mg hydromorphone/day.
HOWEVER, does not account for incomplete cross tolerance when switching between opioids. Due to incomplete cross-tolerance, would reduce dose by 25-50% - likely aim for lower end given ADE.
So, 40mg hydromorphone x .5-.75 = 20-30mg/day
Suggest: Hydromorph Contin 12mg po q12h
122
Opioid Agonist Therapy (OAT) is a useful approach for what patients? (7)
1. Rotating/switching patients with opioid use disorder (OUD)
2. Concurrent psychiatric conditions
3. > 5yrs of opioid use
4. Opioid-induced hyperalgesia (buprenorphine kappa receptor antagonism)
5. Withdrawal-mediated pain (long t1/2 = longer duration of action)
6. Opioid-related dysphoria (buprenorphine kappa receptor antagonism)
7. Pregnancy (methadone)
123
What are 3 good OAT options?
1. Buprenorphine/naloxone
2. Methadone
3. Slow release oral morphine
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Why is buprenorphine a good OAT option? (3)
1. Due to unique receptor effects, bup may cause less tolerance and hyperalgesia than traditional full opioid agonists
2. The long duration of action of bup can alleviate end-of-dose withdrawal pain. If a short duration of analgesia is noticed, doses may be divided (BID-QID), even temporarily
3. Bup has a strong affinity to the opioid receptor, but does not activate it as fully as other opioids. This means, people often experience fewer AEs
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What do we think about using cannabis for pain at the moment? (3)
1. Cannabis in chronic pain literature has many gaps, maybe neuropathic pain use though
2. Recommend pharmaceutical cannabinoids (nabilone, nabiximols) > "storefront" cannabis
3. Harm reduction approach important with very clear goals and monitoring
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What are the 2 Rx cannabinoids?
Nabilone
Nabiximol
