pain Flashcards
1
Q
chronic pain types
A
Inflammatory: arthritis, throbbing, pulsating
Neuropathic: diabetes, carpal tunnel; burning, tingling, shooting, electrical
Visceral: deep, squeezing
Fibromyalgia, Migraine, phantom (amputation), Psychogenic
2
Q
peripheral receptors
A
Temperature Sensitive: TRP, TRPV (heat), TRPM (cold)
Acid sensitive: ASIC (acid sensing ion channel) – activated by H to conduct Na
Chemical irritant sensitive: histamine, bradykinin
3
Q
vascular neuropathy
A
Hereditary or acquired by diabetes, chemical, infections, diet, trauma, carpal tunnel
Treatments: Na, Ca channel blockers; TRPV1 agonist
4
Q
reflex upon painful stimuli
A
Pain originates at the skin travels afferent nerve to spinal cord, response travels back out efferent nerve
5
Q
characterization of pain
A
temporal features:onset, duration, course, pattern
intensity: average, least, worst, current
location: focal, multifocal generalized, reffered, superficial, deep
quality: aching, throbbing, stabbing, burning, shooting
6
Q
pain fibers
A
Aβ Fibers: non-noxious; very fast
Aδ Fibers: Pain, cold; myelinated = fast; take place in reflex arc of immediate response to pain
C-fibers: pain, temperature, touch, pressure, itch; unmyelinated = slow - Peptidergic: containes substance P (role in chronic pain and pain sensitiziation), Non-peptidergic
Blockade of Aδ Fibers and C-fibers are nociceptors
7
Q
peripheral sensitization
A
Substance P Repeated stimuli (due to chronic pain and inflammation) reduces firing threshold = release prostaglandins and substance P => increased expression of pain receptors and expressing more pain fibers Compared to healthy people: allodynia = painful without stimulus; for example sunburns hurt without any touch Painful stimuli: hyperalgesia = increased sensitivity to pain and touching would be more painful than to any healthy person
8
Q
pain circuitry - spinal
A
Central Sensitization: enhanced activation of glutamate system
- Substance P activates NK1 increasing phosphorylation of AMPA and NMDA = extra sensitive to glutmate = enhanced pain response
- BDNF activates TrkB to activate PKA and phosphorylation of NMDA receptors leading to increased expression and sensitivity of AMPA and NMDA = hypersensitivity to pain
9
Q
pain circuitry - brain
A
Pain transmission travels in from dorsal horn up through ascending nerves through thalamus
Brain sends signals down descending nerves to come back out the dorsal horn
10
Q
opiates
A
natural occurring narcotic opioids from the opium plant (morphine, codeine, thebaine, papaverine, noscapine)
11
Q
opioids
A
all drugs acting on opiod receptors
- Heroin is an opioid
- Oxymorphone is an opioid
- Synthetic derivatives from morphine
12
Q
structure acitivity relationships
A
3-position ester/ether = decreased potency (codeine)
6-position increases activity (hydroxyl or ketone)
14-position hydroxyl = increased potency (oxycodone)
N-allyl gives antagonist (naloxone or naltrexone)
13
Q
metabolism of morphine/phenanthrenes
A
Morphine-3-(50-60%) and morphine-6-glucuronide (10%) are active
Excretion: glomerular filtration
14
Q
opiod receptors
A
GPCR i/o: inhibition of cAMP production -Mu -Kappa -Delta -Nociceptin All FDA-approved drugs target mu receptors or kappa/delta receptors
15
Q
Transduction for Opioid Receptor
A
Gi signal activates K+ leading to hyperpolarization that inhibits action potentials
Gi signal decreases cAMP production = decreased Ca = no release of neurotransmitter or pain signals
16
Q
Mu opioid receptor
A
Beta-endorphins: POMC, anandamide, 5HT, DA
Therapeutic Targets: Hard to target in chronic pain due to tolerance, Can lead to sedation, and be an anti-tussive
17
Q
Mu opioid receptor side effects
A
Mechanism of Action
Respiratory Depression: originates from mu receptors in brain stem
Constipation: mu receptors in GI tract = motility is stopped
Pruritus, Addiction, Urinary Retention
Nausea/Vomiting: receptors in chemoreceptor trigger zone in medulla
Miosis: oculomotor nerve (meperidine does not cause)
Opioids as anti-diarrheal? Could be safe and effective for opioids not crossing blood brain barrier, but not ideal for addictive properties
18
Q
kappa opioid receptor
A
Dynorphins = natural ligand
Potential for use of treatment of addiction
Counterbalance mu opioid receptor effects
19
Q
delta opioid receptor
A
Enkephalins = natural ligand
More dynamic expression upon chronic stimuli
20
Q
opioid receptor trafficking
A
Opioid agonist binds to mu receptor
Decreased cAMP production
Phosphorylation of GPCR to desensitize
Increased affinity of GPCR to β-arrestin
Binding of β-arrestin = mu receptor internalized
Mu receptor internalized = temporarily reduces receptors on surface
Resensitization and recycling of receptors back to surface
Controls amount of receptors available to stimulate and prevents tolerance
21
Q
opioid tolerance
A
Morphine (not endogenous peptide) binds to mu receptor
Decreased cAMP production
Activation doesn’t lead to desensitization and phosphorylation of receptor
Morphine continues to inhibit cAMP production -> body must find different way to adapt and increase cAMP production
Chronic morphine: cell has adapted to continuing to produce cAMP - cAMP superactivation = opioid induced hyperalgesia
22
Q
opioid clinical therapeutic effects
A
Pain: traumatic pain; surgergy, anesthesia, post-op pain, cancer pain, chronic pain Cough: codeine; dextromethorphan SSRI, NMDA antagonist (at high doses) Constipating Effect (anti-diarrheal): Diphenoxylate with Atropine; Loperamide (low BBB penetration)
23
Q
non-phenanthrene opiods clinical therapeutic effects
A
Tramadol, Tapentadol: mild opioid analgesic, SNRI properties, management of mild neuropathic pain
Meperidine: active metabolite can accumulate and cause CNS irritability and myoclonic seizures
Why use meperidine? Nonresponsive to other opioids or allergy
24
Q
opioids with NMDA effects
A
Methadone: primarily used for opioid dependence; NMDA antagonist
Levorphanol: NMDA antagonist
25
mixed agonis-antagonist and partial agonist opioids clinical effects
Partial agonist: limit euphoric effects and abuse
Partial agonist = partial antagonist = can precipitate withdrawal because not getting full effect
Butorphanol, Pentazocine: partial kappa agonist/ mu antagonism
Side effects: less dysphoria, increase BP and HR
Nalbuphine: full kappa agonist/ mu antagonist
Antagonism produces withdrawal
Buprenorphine: partial mu agonist, weak kappa agonist, and delta antagonist
26
negative consequences of opioid use
Side effects: comfortable limited side effects -> constipation/somnolence -> itch, urinary retention -> respiratory depression/death
Itch: opioid release histamine from mast cells (side effect, not allergy)
Hyperalgesia - Tolerance: increase dose required to produce equivalent effect; Hyperalgesia: compensatory changes, altered excitability of target neurons; lower stimulus intensity = same amount of pain
27
Therapeutic Applications of NSAIDs
Analgesic: headache, chronic postsurgical pain, myalgias/arthralgias, inflammatory pain
Antipyretic: fever
Anti-inflammatory: bursitis, tendonitis, osteoarthritis, RA, gout/hyperuricemia
28
inflammation
Acute: vasodilation, increased permeability
Subacute: infiltration
Chronic: proliferation
Mediators: eicosanoids and arachidonic acid metabolites
29
NSAID are COX inhibitors in the arachidonic acid pathway
COX-1:
-Constitutively expressed in platelets, stomach, kidney
-PGE2 and PGI2 are protective in stomach by inhibiting acid secretion, promoting mucus, inhibition (caused by NSAIDs) can lead to stomach ulcers
-TXA2 synthesis induces platelet aggregation = blood thinning
COX-2: present constitutively in brain and spinal cord; induced in inflammation by cytokines and inflammatory mediators
30
aspirin
irreversibly inhibits COX1/2 by acetylation of COX
Main use for anti-coagulation
No tolerance to analgesic effects
31
other NSAIDs
reversible inhibitor of COX ½
Some inhibit leukotriene synthesis = great anti-inflammatory effect
Indomethacin and Diclofenac
32
Arylpropionic Acids
Ibuprofen, Naproxen
Better tolerated than aspirin
Half-life: naproxen 14 hours vs. ibuprofen 2 hours
33
acetic acid derivatives
Diclofenac: increased risk of peptic ulcer and renal dysfunction; used with Misoprostol (PGE1 analog) to protect stomach
Indomethacin: high incidence and severity of side effects long-term
Sulindac: still significant side effects
34
acetaminophen
High effective as an analgesic and antipyretic
| Advantages: no GI toxicity, no effect on platelets, no Reye’s correlation,
35
salicylates AE
GI distress, can treat with misoprostol (Why does it work? Produces prostaglandins that salicylates inhibit)
-Overdose: metabolic acidosis and respiratory alkalosis
36
NSAIDs AE
GI intolerance/ ulceration; renal function (higher risk with long term use); transient inhibition of platelet aggregation; inhibition of uterine motility: therapeutic use for delaying preterm labor
37
acetaminophen AEs
Renal toxicity
Dose-dependent potentially fatal hepatic necrosis: increased risk with high alcohol consumption -> alcohol up-regulates CYP mediated metabolism to NAPQI = toxic metabolite
Appears in many combination products: Lortab, Percocet
38
selective COX2 inhibitors
Nonselective (COX 1 /2 ): aspirin, acetaminophen, non-salicylates NSAIDs => stomach ulcers, bleeds
Selective COX-2: reduce ulcers and GI bleeds
COX-2 inhibitor Vioxx: high chance of blood clots, strokes, and heart attacks
Black box label for Celecoxib
39
Na channel
expressed in peripheral neurons, role in neuropathic pain, role in congenital insensitivity to pain
40
topical anesthetics
Na channel blockers
Lidocaine
Bupivicaine
Benzocaine: OTC use, lower allergy risk
41
Na channel blockers
Lamotrigine: off label for neuropathy and migraine
Amitriptyline: post-herpetic neuralgia, polyneuropathy, fibromyalgia, visceral pain
Carbamazepine: trigeminal neuralgia
42
SNRIs as Na channel blockers
Duloxetine: diabetic pain, fibromyalgia, peripheral neuropathy
Venlafaxine: off label diabetic neuropathic pain
SNRIs lacking sodium channel functionality: Milnacipran, Tapentadol
SSRIs? They would not be helpful by themselves, but could be as an adjunct as pain and depression can often go together.
43
Ca channels
Prevent neurotransmitter release and pain
| Gabapentin, Pregabalin, Ziconotide; Levetiracetam
44
opioid use for surgical anesthesia
Equianalgesic Dose: convert each opioid to equi-analgesic morphine dose -> calculate daily equivalent dose of new opioid
Be able to use pain medication comparison table to convert doses
When to use - Surgery: fentanyl, sufentanil, remifentanil for fast-onset and short duration; Post-op/ Epidural: hydromorphone, morphine for potency and greater half-life; Management: oxycodone, Hydrocodone, Oxycontin, Zohydro for oral bioavailability, longer half-life; Terminal cancer pain: morphine for cost effectiveness; Opioid Intolerance: meperidine as constipation is less common
45
surgical anesthesia
General anesthesia: loss of consciousness; given by inhalation or intravenous injection; airway is instrumented with an endotracheal tube if procedure is long
Neuraxial anesthesia: local anesthesia within the cerebral spinal fluid or epidural space; technique can be utilized for surgeries involving the abdomen and lower body
Peripheral nerve block: local anesthetic near peripheral nerves; involved in surgeries involving extremities
46
components to surgical anesthesia
Muscle Relaxant: prevent muscle spasms
Anesthesia: volatile gas
Analgesia: opioids
47
general anesthesia
Premedications prior to GA: Anxiolytics may be required like midazolam, Antiemetic: scopolamine, Opioids
Patients are intubated - Antisialogogue = glycopyrrolate = decrease salivary, bronchial, GI secretions; Ketamine: bronchodilator helpful for asthmatic patients
48
twilight anesthesia
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Short duration surgery
Anxiolytic + Hypnotic + Amnestic
Propofol: Hypnotic/Amnesia, analgesis
Midazolam: sedation, anxiolysis
Fentanyl: sedation, analgesia
Risk of mixture: sedation
```
49
muscle relaxants
Non-depolarizing: antagonists at nicotinic Ach receptors - Atracurium, rocuronium; Easily reversibly by neostigmine
Depolarizing: agonist at nicotinic Ach receptors (persistent depolarization makes muscle resistant to further stimulation) - Succinylcholine chloride, Not easily reversible
50
Inhalant Gases for Anesthesia
sevoflurane, desflurane, isoflurane, Nitrous oxide, halothane, chloroform, diethylether
51
IV anesthetics
barbiturates, benzodiazepines, etomidate, dexmedetomidine, propofol, ketamine
52
barbituate and muscle relaxant
not sufficient for surgery - need opioid
53
IV reversal agent
Flumazenil: reverses effect of benzodiazepines
Naloxone: reverses effect of opioids
Neostigmine and sugammadex: reverse effects of non-depolarizing muscle relaxants
Naloxone has a rapid onset and short-half life versus naltrexone has a longer half-life - Shouldn’t use naltrexone to reverse analgesis because it will be difficult to give analgesics when they are need post-surgery due to longer half-life
54
types of pain
Nocioceptive: due to injury to tissue
-Visceral: deep, dull, aching, squeezing, or pressure-like pain
-Somatic: musculoskeletal pain - Superficial: throbbing, burning, or prickling; Deep: dull, aching pain
Neuropathic: nerve injury which causes burning, tingling, or numbing pain
55
subjective pain assessment
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Palliative or precipitating factors
Quality of pain
Region of pain location
Severtiy
Timing
U impact on yoU
what have you tried?
```
56
objective pain assessment
behavioral changes
| physioogical: dilated pupils, paleness, sweating, tachycardia, tachypnea
57
pain assessment instruments
Unidimensional pain intensity scales: Verbal, Numeric, Visual, Wong-Baker, FLACC
Multidimensional pain intensity scales: Pain diary/drawing, Wisconsin Brief Pain Questionnaire, McGill Pain Questionnaire
58
goals of therapy
Correct underlying cause of pain if possible
Minimize pain and symptoms from pain/injury
Realistic pain goal (may not be able to eradicate pain)
Limit pharmacotherapy side effects
Improve quality of life (QOL) and activities of daily living (ADLs)
59
nonpharm treatment
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Correct underlying cause of pain (surgery, avoidance)
RICE (rest, ice, compression, elevation)
Psychotherapy/behavioral modifications
Physical therapy
Massage
Acupuncture
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60
pharm treatment approach
step wise - step up with persisting pain and step down with toxicity or if pain subsides
1) non-opioid +/- adjuvant
2) opioid (mild-mod) +/- adjuvant
3) opioid (mod-severe) +/- adjuvant
61
selecting analgesic
patient specific factors: access, renal/hepatic impairment, past trials, age, AEs, severity
medication specific: dosage form, abuse, duration and onset, cost, potency, interactions
62
PRN vs. scheduled analgesics
PRN analgesia: medication administered only when patient is in pain, idea is to minimize exposure to limit toxicity and only treat when pain is above a threshold, symptom triggered
Scheduled or around-the-clock (ATC) analgesia: given at a set interval for preemptive pain management, when pain is constant, or PRN pain medication has to be administered frequently, Can still use breakthrough analgesia PRN, May be better option for chronic, continual pain
63
Step 1
NSAIDs and acetaminophen
64
NSAIDs
Initial adult analgesic doses:
Aspirin*: 325 PO Q4H PRN
Ibuprofen*(Motrin®, Advil®): 400 mg PO Q4H PRN; Pediatrics: 5-10 mg/kg PO Q6H PRN
Ketorolac (Toradol®): 30 mg IM/IV Q6H PRN (do not use longer than 5 days)
Naproxen*(Aleve®): 440 mg PO Q8H PRN
Utility: Mild pain, anti-inflammatory, antipyretic
Side effects: Bleeding, Nephrotoxicity, Fluid retention/hypertension, Black box warning: increased cardiovascular events
Clinical pearls: Caution use in geriatric patients
65
acetaminophen
Initial adult analgesic dose (OTC)
Acetaminophen (Tylenol®): Adults: 325 mg PO Q4H PRN, Pediatrics: 10-15 mg/kg PO Q4H PRN
Maximum dose: Adults: 3-4 g/day** (Liver disease: 2 g/day), Pediatrics: 75 mg/kg/day
Utility: Mild pain, antipyretic
Side effects: Hepatotoxicity (1/3 of ODs are unintentional)
Clinical pearls: If using combination products with acetaminophen, be aware of total daily dose, Gold standard for osteoarthritis due to fewer side effects than NSAIDs in geriatrics
66
analgesic adjuvants
Non-pharmacologic treatments (discussed above)
| Neuropathic treatments: Anticonvulsants, SNRIs, TCAs
67
anticonvulsants
Initial adult dosing:
Gabapentin (Neurontin®): requires titration 300 mg PO day 1, then 300 mg PO BID day 2, then 300 mg PO TID day 3 - Can titrate up further (max 3,600 mg/day)
Pregabalin (Lyrica®): 150 mg PO daily (either as single dose or 75 mg PO BID)
Utility: Fibromyalgia, Neuropathy, Post-operative pain
Side effects: Sedation, Dizziness
Clinical pearls: Titrate up dose *to limit sedation initially, Further titration must balance benefit with toxicity
Can be used as adjunctive therapy to decrease requirements of other analgesics
68
SNRIs
Initial adult dosing
Duloxetine (Cymbalta®): 30 mg PO daily
Venlafaxine (Effexor®) 37.5-75 mg PO daily
Utility: Fibromyalgia, Neuropathy, Depression
Side effects: Headache, Sedation, Weakness, Nausea, Hypertension
Clinical pearls: Titrate up doses to minimize side effects, With CrCl under 30 mL/min avoid duloxetine and decrease venlafaxine daily dose by 50%
69
TCAs
Initial adult dosing
Amitriptyline (Elavil®): 25 mg PO daily
Utility: Neuropathy (off-label), Depression
Side effects: Anticholinergic side effects, Sedation
Clinical pearls: Later line option for neuropathy due to side effect profile
70
full agonist opioids
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Morphine
Hydrocodone
Oxycodone
Hydromorphone
Fentanyl
Methadone
Meperidine
```
71
weak agonist opioids
codeine, tramadol
72
opioid antagonist
nalaxone
73
mixed agonist/antagonist
buprenorphine/nalaxone
74
codeine
Mild-moderate pain, antitussive
converted to morphine
Initial adult analgesic dose: 15-30 mg PO Q4H
Available as oral tablet or solution
Due to differences in rate of metabolism, cautioned in pediatrics under 12 years
75
tramadol
mild-moderate pain
Initial adult analgesic dose:
50 mg PO Q4H
CrCl under 30 mL/min: 50 mg PO Q12H
Side effects: Sedation, Lowers seizure threshold
Opioid-like but decreased potency and decreased side effects
76
morphine
```
Moderate-severe pain
Initial analgesic dosing:
Adults: 15 mg PO Q4H
Pediatrics: 0.15 mg/kg PO Q3H
Preparations:
-Oral: IR, ER (12 hr, 24 hr), solution
-Parenteral (IV, IM, subQ)
-Rectal: suppository
Side effects: Itching more common with morphine than
other opioids
Renally cleared so caution in patients with renal impairment
```
77
hydrocodone
moderate pain
initial adult dosing
Norco® 5/325 mg PO Q4H PRN
Oral preparations: Norco®: IR tablet, Abuse deterrent ER tablet (hydrocodone alone)
Renally excreted but less accumulation than oxycodone
78
oxycodone
moderate-severe pain
initial adult dosing:
Oxycodone IR 5 mg PO Q4H PRN
Oxycodone/acetaminophen (Percocet®) 5/325 mg PO Q4H PRN
Oxycodone ER 10 mg PO BID**
Preparations: Oxycodone: oral (IR, ER, solution), parenteral solution, Oxycodone/acetaminophen: oral (IR, ER, solution)
renally excreted
79
hydromorphone
```
severe pain
Initial adult dosing: 2 mg PO Q4H PRN
Preparations:
-Oral: IR, ER, solution
-Parenteral solution
-Rectal: suppository
Caution in renal impairment
```
80
fentanyl
```
severe pain
Initial adult dosing:
25-50 mCg IM/IV Q1-2H PRN, Short duration of activity when given parenterally
Preparations:
-Oral: buccal, sublingual
-Parenteral solution
-Transdermal patch
*Safer option to use in renal impairment as mostly excreted as metabolites (
```
81
methadone
severe chronic pain, opioid
detoxification
Initial adult analgesic dosing:
2.5 mg PO Q8H PRN (long duration of action)
Preparations:
-Oral: solution, tablet
-Parenteral solution
Monitor ECG as QTc prolongation can occur
Hepatically metabolized so safer to use in renal impairment
Use for detoxification limited to set prescribers
82
meperidine
moderate to severe pain
Preparations: Parenteral solution
Side effects: Neurotoxicity with accumulation of an active metabolite (increased risk with renal impairment)
Limited usually to one time dosing for surgery
if used, monitor renal function, mental status, and respiratory function
Avoid with CrCl under 30 mL/min
83
nalaxone
Utility: Opioid overdose, Opioid induced respiratory depression, Co-formulated with agonists to minimize abuse potential
Dosing:
Parenteral: 0.4 mg subQ, IM, IV Q2-3 minutes until desired response
-Evzio® auo-injector: 0.4 mg
Intranasal: 4 mg/spray 1 spray Q2-3 minutes until desired response
If not responding to naloxone, likely other cause of symptoms
As it is an antagonist, can induce opioid withdrawal symptoms
84
buprenophine/nalaxone
suboxone
Utility: Opioid dependence (including heroin)
Preparations: Buccal tablet and film, Sublingual tablet
Buprenorphine is a partial agonist so has an analgesic ceiling effect
Naloxone is utilized as an abuse deterrent
Prescribing limited to physicians with specific DEA number
85
opioid initiation
Initiation of opioids based on previous opioid exposure and source of pain - Must balance analgesic benefit with toxicity
IR vs. ER/CR formulations:
-BOTH have boxed warnings from the FDA due to safety concerns
-If acute pain, patients should be started on parenteral or IR formulations
-Chronic pain: ER/CR provides more pre-emptive pain control and stable analgesia, If using ER/CR, determine daily dose and split between ER, Use IR PRN for breakthrough pain (10% of total daily dose available as PRN)
86
patient controlled analgesia
PCA: patient given active role in administration timing of IV analgesia
Utility for severe acute non-malignant pain: Post-operative, Pancreatitis
*Prescriber sets parameters of dose and frequency which a patient can receive analgesia through the IV PCA - Can also restrict the number of times a dose is administered in a set period (i.e. max dose for 4 hour period)
Consider a basal rate for patients who underwent trauma/surgery, pushing PCA maximally, or previous opioid exposure
87
PCA dosing
Opioid naïve patients (start cautiously):
-Fentanyl (10 mCg/mL) 10 mCg Q4-10 mins PRN
-Hydromorphone (0.2 mg/mL) 0.2 mg Q5-10 mins PRN
-Morphine (1 mg/mL) 1 mg Q5-10 mins PRN
opioid tolerant patients: Use conversion table to figure out initial dosing based on previous opioid use, May require a higher dose than on at home if acute on chronic pain, May consider basal rate for preemptive pain control in patients on chronic opioid therapy
88
switching between opioids*
1. Calculate daily consumption and then use table to find equianalgesic dose
2. Convert to total daily dose of desired agent
3. Due to cross-tolerance, reduce the equal analgesic dose by 25- 50%
4. Split total daily dose into appropriate dosing interval based on opioid selected
89
opioid equivalencies*
parenteral:
130 codeine = 0.1 fentanyl = 1.5 hydromorphone = 10 morphine
oral:
200 codeine = 30 hydrocodone = 7.5 hydromorphone = 30 morphine = 20 oxycodone
90
opioid related side effects
Constipation, Nausea/vomiting, Itching, Respiratory depression, Sedation, Addiction, Abuse, Tolerance, Overdose, Withdrawal
91
GI side effects
Opioids can reduce peristalsis resulting in constipation and nausea/vomiting
Constipation treatments:
-OTC: Stimulant laxative (Bisacodyl, Senna +/- docusate)
-Prescription: Methylnatrexone, Naloxegol
Utility: BEST to be proactive with laxatives
Non-pharmacologic therapies: Increase fluid and fiber (25-30 g/day) intake, Encourage physical activity
Nausea/vomiting treatment: Take opioids with food, Pharmacologic treatment: anti-emetics
92
itching
Itching believed to be caused by histamine release with opioids - Most common culprit is morphine, Dose dependent side effect
Treatment: Symptomatic management - Antihistamines (i.e. diphenhydramine), Preparations: oral, topical, parenteral, Side effects
Preventing future itching: Reduce dose of opioid, Switch to alternative opioid, Different route of administration
93
sedation and respiratory depression
Opioid induced sedation requires monitoring and potential dose reductions: Dose dependent side effect
Sedation treatment: Reduce opioid consumption (Decrease dose of current opioid; Switch to less potent opioid), Naloxone
Respiratory depression caused by opioids decreasing respiratory drive while patient is sedated: Usually defined as respiratory rate under 8 bpm
Respiratory depression treatment: Wake up and encourage to take deep breaths, Naloxone, Reduce opioid consumption (Decrease dose of current opioid, Switch to less potent opioid)
94
addiction and abuse
Due to euphoric effects, opioids have a high risk of addiction and abuse
Evaluate true need for and duration of opioid therapy
If patient warrants chronic opioid therapy, Indiana law requires a pain contract
Prescription drug monitoring programs (PDMPs) can assist healthcare providers in monitoring prescriptions for opioids
95
tolerance
With chronic therapy, opioid receptors because desensitized and require higher doses to produce analgesia
Requires a balance
96
overdose
Intentional or unintentional
| Treatment: naloxone
97
withdrawal
Symptoms: agitation, anxiety, increased sweating, insomnia, restlessness
Treatment: Symptomatic management - Clonidine; Detoxification treatment - Methadone
98
pain contracts
Indiana requires pain contracts for patients with prescriber if:
over 3 months of opioid therapy with one of the following:
-over 60 tablets/capsules of an opioid/month
-over 15 mg/day of oral morphine equivalents
This requires: Informed consent on potential harm with opioid therapy, Annual drug monitoring test, Does not allow for prescribing UNLESS patient shows up for periodic visits
99
CDC guidelines for prescribing opioids
1. If opioids are used, use with non-pharmacologic and non-opioid therapies
2. Establish realistic treatment goals for ALL patients
3. For acute pain, use lowest effective dose with shortest duration possible
4. For chronic pain, start with IR opioids and start the lowest effective dosage
a) Avoid titrating to > 90 mg oral morphine equivalents/day
b) Evaluate every 1-4 weeks for opioid benefit and harm
5. Review prescription drug monitoring program (PDMP) data
6. Avoid concomitant use of opioids and benzodiazepines if possible
100
step 2 treatment
options: codeine, tramadol, norco, morphine
101
step 3 treatment
options: oxycodone (+/- acetaminophen), fentanyl, hydromorphone, methadone, meperidine
102
patient education
Realistic pain goals
Educate on non-pharmacologic strategies (if applicable)
Discuss administration and frequency
Counsel on potential side effects and how to minimize
103
neuropathy treatments
first line: anticonvulsants (gabapentin, pregabalin), SNRI (duloxetine, venlafaxine)
second line: TCAs (amitriptyline)
Adjusting therapy: Titrate up doses due to side effects, Add additional treatments if a medication is maximized, Opioids used only for acute severe pain as not a chronic solution
