IC6 opioids, pain Flashcards
pain ladder
- Pain ladder for pain assessment and management based on pain severity
- Individualised therapeutic planning required
MILD 1-3: non-opid +/- adjuvant
MOD 4-7: opioid for mil-mod +/- non opioid +/- adjuvant
SEVERE ≥8: opioid for mod-severe pain +/- non opioid +/- adjuvant
general principles for pain management
- select most app med based on pain diagnosis, comorbid, potential DDI
- analgesic regimen: opioid, nsaid, paracetamol, adjuvant
- treat analgesic AE (OIC)
- psychosocial support
- provide pt and fam/ caregiver education
- optimise integrative interventions
Initiation of opioids should start with
titration of short-acting opioids as needed, lowest effective dose for shortest duration needed.
* short acting: rapid analgesic effect
* ROA: depends on pt analgesic needs
* (optimise nonopioid therapies while on opioid.
starting dose
The lowest starting dose for opioid-naïve patients is often equivalent to a single dose of approximately 5–10 MME
Max daily dosage of 20–30 MME/day. (morphine mg equivalent)
pt with chronic persistent pain
stable doses of short-acting opioids should be provided with (ER) or (LA) opioids + “rescue dose” to manage breakthrough or transient exacerbations of pain.
- The rescue dose is usually equivalent to 10%–20% of the total opioid daily consumption
- may be given every hour PRN severe exacerbations of pain.
- Rapid onset and short duration are preferred as rescue doses.
The repeated need for numerous rescue doses per day may indicate the need to adjust baseline treatment
initiation of ER/LA opioids
- received certain dosages of immediate-release opioids daily (e.g., 60 mg daily of oral morphine)
- additional caution with ER/LA opioids and consider a longer dosing interval when prescribing to patients with renal or hepatic dysfunction
* interindividual PK variability and organ function = decreased CL --> accumulation of drugs to toxic levels * reducedose by 25-50% due to incomplete cross-tolerance, risk of overdose
management of psychosocial support and education
educate on Diversion, misuse of opioids and addictive potential
management on constipation
- Constipation routinely evaluated and managed
□ Prophylactic - pharmacologic therapy (e.g., a stimulant laxative such as senna, with or without a stool softener) for regular bowel movements if opioids are used for more than a few days.
□ Stool softeners or fiber laxatives without another laxative should be avoided.
management of withdrawal
- discuss an opioid tapering plan when opioids will be used around the clock for more than a few days.
□ Limiting opioid use to the minimum needed to manage pain (e.g., taking the opioid PRN if needed less frequently than Q4H
□ help limit development of tolerance and therefore withdrawal after opioids are discontinued.
Non-opioid analgesics
- Paracetamol (possible hepatotoxicity, renal impairment)
□ Combi with opioid (hydrocodone, codeine), caution due to liver injury (max 4g/d) - NSAIDs
□ Prophy w/ PPI, misoprostol
□ Use as combi to reduce opioid dose (sedative, cognitive function effects)
□ TOPICAL can be used - Adjuvant — gabapentin, pregabalin, SSRI, SNRI, TCA, Corticosteroids, local anaesthetics (lidocaine)
MOA of adjuvants (antidep, anticonvulsants, CS)
to enhance opioid analgesia and treat neuropathic component of pain, reduce dose of opioids (less AE)
- Antidep: Risk of SS, qtc prolongation, potential CYP2D6 inhibition (fluoxetine, fluvoxamine, bupropion, duloxetine)
- Anticonvulsant: gabapentin
- Corticosteroids: tx bone pain and neuropathic pain syndrome + anti-inflamm effects
non-pharm for pain management
stress reduction, CBT, biofeedback. Walking supports, massage, heat. Ice, TENS (transcutaneous electrical nerve stimulation), acupuncture
morphine PK
Morphine is metabolized in the liver glucuronidation by uridine 5′-diphospho-glucuronosyltransferase (UGT) phase II enzymes.
to morphine-6-glucuronide and morphine-3-glucuronide
- M3G: no effect. M6G: greater analgesia potency and toxicity effect
- both of which are excreted by the kidneys.
morphine DF
morphine SYRUP is not a controlled drug in sg
- 5 to 15 mg of oral short-acting morphine sulfate or equivalent for opioid-naıve patients
- IV is 1/3 of PO dose (2-5mg) for naive
- 60mg/d means tolerant
monitoring of opioids use
- Pain relief
- respiratory and mental status/alertness (especially in patients on concomitant CNS depressants, including benzodiazepines)
- BP, heart rate
- signs of misuse, abuse, or substance use disorder
- symptoms of serotonin syndrome such as mental status changes (eg, agitation, hallucinations, coma), autonomic instability (eg, tachycardia, labile BP, hyperthermia), neuromuscular changes (eg, hyperreflexia, incoordination)
- GI symptoms
morphine –> tramadol
30mg PO morphine –> 300mg PO tramadol
tramadol MOA and Dose
weak opioid, mu opioid receptor binding and monoamine (serotonin and norepinephrine) reuptake blockade (mixed mechanism).
100mg TDS
Tab 200mg, 100/ 150mg PR, 50mg
37.5mg (w/ 200mg paracetamol)
Suppository
50mg/ml inj
tramadol DDI
CNS Depressants: Alcohol, other opioids, CBZ (X), Phenobarbital (D), Primidone (D), TCAs (D)
Serotonergic risk: MAOis (e.g. Isocarboxazid, Phenelzine, Moclobemide, Selegiline; X), Linezolid (D)
2D6i: strong: Fluoxetine, sertraline
Paroxetine, Duloxetine, Bupropion, Quinidine, ritonavir, terbinafine.
3A4 inhibitors: Fexinidazole (X), Fusidic Acid (X)
cyp2d6 PK
codeine, hydrocodone, methadone, oxycodone, tramadol
need CY2D6 to convert to active metabolite for analgesic effect
- PM: low efficacy
- URM: toxic
