Pain/Related Conditions: Pain Flashcards
Most common medications for mild pain
tylenol
NSAIDs
Opioids are most appropriate for what kind of pain?
Moderate to severe
When should adjuvants be considered for pain?
at all severities of pain
Tylenol max daily dose
Maximum < 4,000 mg/day
Boxed warnings for Tylenol
severe hepatotoxicity with dosing > 4g/day or suing multiple Tylenol containing products
Tylenol pediatric (< 12 yrs old) dosing
10-15 mg/kg Q4-6H
Tylenol drug interactions
can be used with warfarin, but dosing > 2g/day can increase INR
avoid/limit alc use due to risk of hepatotoxicity
What do non-selective NSAIDs block
They block the synthesis of both COX enzymes (COX-1 & COX-2)
What do COX enzymes do
catalyze conversion of arachidonic acid to PGs and thromboxane A2 (TxA2)
COX-2 selective NSAIDs
block synthesis of COX-2 only, decreasing GI risk
COX-1 protects gastric mucosa
How does Aspirin block COX?
irreversible COX-1 and COX-2 inhibitor
Non-aspirin NSAID warnings
GI risk = inc risk of serious GI bleed and ulceration
CV risk = can increase risk of MI and stroke
No NSAIDs after CABG, antiplatelet therapy (aspirin) recommended
Side Effects of All NSAIDs
used cautiously or avoid in renal failure
can inc BP, avoid in uncontrolled HTN
don’t use 3rd trimester ( > 30 wks)
Nausea, taking with food can help
can cause photosensitivity
Ibuprofen daily maxs
OTC: 1200mg/day
RX: 3200mg/day
Peds 40mg/kg/day
Which IV NSAIDs can be used within 14 days of birth to close a patent ductus arteriosus
indomethacin
ibuprofen
Ibuprofen self-treatment OTC recommended limit
< 10 days
Indomethacin (Indocin) side effects
high risk of CNS side effects = avoid in psych conditions
Ketorolac boxed warnings
max combined duration of IV/IM and PO/Nasal is 5 days in adults
Ketorolac warnings
inc bleeding
acute renal failure
liver failure
When is Sulindac used
sometimes in reduced renal function, and in patients on lithium who require an NSAID
Piroxicam notes
high risk for GI toxicity and severe skin reactions, inc SJS/TEN
COX-2 selective drugs
Celecoxib (Celebrex)
Diclofenac (Voltaren)
Meloxicam (Mobic)
Etodolac
Nabumetone
Celecoxib Contraindications
sulfonamide allergy
Celecoxib notes
has highest COX-2 selectivity
avoid in pregnancy
Diclofenac Boxed warnings
avoid Arthrotec (diclofenac + misoprostol) in females of childbearing potential
Meloxicam, Etodolac, and Nabumetone COX selectivity
Has some COX-2 selectivity
Cardioprotection dosing of aspirin
81-162mg once daily
Aspirin warnings
Avoid with NSAID hypersensitivity
Avoid Aspirin in children and teenagers with viral infection due to Reye’s syndrome risk
Aspirin side effects
dyspepsia
heartburn
bleeding
nausea
Aspirin notes
PPI can be used to protect gut, weigh pro vs cons of long term PPIs
OD can cause tinnitus
Opioid boxed warnings
addiction, abuse and misuse can lead to OD and death
respiratory deprssion
inc risk with other CNS depressants
No alc ER morphine, hydrocodone, oxy
accidental ingestion can be fatal for child
crushing, dissolving or chewing LA can lead to OD
neonatal withdrawal when used during pregnancy
Physiological adaptation (physical dependence) definition
almost everyone who uses will experience physical withdrawal when med stopped, late dose or miss dose
Addiction defintion
strong desire or compulsion to take drug despite harm, drug-seeking behavior
Opiod use disorder definition
problematic pattern of opioid use that causes significant impairment or distress
have to have had unsuccessful trials to reduce or control opioid useT
tolerance definition
higher opioid dose needed to produce same lvl of analgesia
Opioid hyperalgesia definition
opioid dose inc to treat pain but pain gets worse instead of better
Break-through-pain opioid definition
sharp spikes of severe pain that occur despite the use of ER opioid
often ER dispensed with BTP meds to be used in event it occurs
All opioid sides effects
constipation
nausea
vomiting
somnolence
dizziness/lightheadedness
risk of respiratory depression
pruritus common
Codeine boxed warnings
respiratory depression and death in children found to be ultra-rapid metabolizers CYP 2D6 polymorphism after tonsillectomy and/or adenoidectomy
Codeine contraindications
dont use children < 12yrs old and < 18yrs following tonsillectomy/adenoidectomy
Codeine side effects
has high degree of GI side effects including constipation
Codeine notes
pro drug, gets metabolized to morphine
Fentanyl boxed warnings
using w/ strong CYP3A4 inhibitors can inc effects and respiratory failure
Fentanyl side effects
excessive sweating
dry mouth
asthenia
loss of appetite
application side redness/erythema
Fentanyl notes
not used in opioid naive patients
pts on 60mg/day morphine equivalent or at least 7 days therapy can be converted to Fentanyl
Fentanyl patch notes
only apply 1
apply to hairless skin
dont cover with heating pad
flush down toilet when done
can only cover with Bioclusive or Tegaderm
Hydrocodone + Tylenol is….
Norco
vicodin
Oxycodne + Tylenol is…
Percocet
Hydrocodone boxed warnings
starting CYP3A4 inhibitions or stopping inducers can cause fatal OD
Hydromorphone Boxed warnings
risk of med error with high potency injection 10mg/ml vs 2mg/ml
Hydromorphone notes
start with low dose, high risk of OD due to potency
Methadone boxed warnings
Life threatening QT prolongation and serious arrhythmias have occurred
Methadone uses
txm fo pain and for detox and maintenance txm of opioid use disorder
Methadone notes
variable half-life, hard to dose safely
can dec testosterone = sexual dysfunction
Meperidine warnings
renal impairment and elderly at risk for CNS toxicity
avoid within 2 weeks of MAOi
Meperidine notes
no longer recommended as analgesic
short half life
Morphine side effects
pruritic
dry mouth
Oxycodone Boxed warnings
initiation of CYP3A4 inhibitors or stopping inducers can lead to fatal OD
Oxycodone side effects
pruritus
dry mouth
Oxycodone notes
avoid high fat meals with higher doses unless re-formualted OxyContin
Oxymorphone should be taken on a….
empty stomach
IV to oral Morphine
10mg IV to 30mg oral
IV to Oral Hydromorphone
1.5mg IV to 7.5mg oral
Morphine to Hydromorphone
10mg = 1.5mg IV
30mg oral = 7.5mg oral
Oxycodone to Hydromorphone oral
20mg oral = 7.5mg hydro oral
Hydrocodone oral to oxycodone
30mg hydro = 20mg oxy
How to convert dosing
add up total used in 24hrs
use conversions to convert to drug of choice
reduce dose by 25% unless exam doesnt ask to reduce***
divide into appropriate interval and dose
Break through dosing is usually
10-15% of total daily baseline opioid dose
Which formulations should be used for breakthrough pain?
use IR formulation
Opioid-induced respiratory depression risks
hx of previous OD
substance use disorder
using larger doses ( > 50mg morphine)
use w/ benze, gabapentin, pregabalin
comorbid illness
Peripherally-acting mu-opioid receptor antagonists (PAMORAs) MOA
block opioid receptors in the gut to reduce constipation without affecting analgesia
only effective when constipation is secondary to use of opioid
PAMORAs
Methylnaltrexone
Naloxegol
Naldemedine
PAMORAs Warnings
GI perforation
PAMORAs side effects
abdominal pain
flatulence
diarrhea
nausea
Tramadol boxed warnings
Respiratory depression and death in children following tonsillectomy and or adenoidectomy who are ultra-rapid metabolizers
Tramadol warnings
Seizure risk
risk of serotonin syndrome
Hypoglycemia
CNS depression
Tramadol Contraindications
children < 12 and < 18 after tonsillectomy/adenoidectomy surgery
MAOi concurrent or within 14 days
Tramadol side effects
Dizziness
constipation
nausea
somnolence
Tapentadol (Nucynta) warnings
can inc seizure risk, risk of serotonin syndrome
Naltrexone shouldn’t be started until patient is opioid free for how long?
7- 10 days
Buprenorphine MOA
partial mu-opioid agonist
agonist at low doses, antagonist at higher doses
low dose - pain, high dose = addiction txm
Gabapentin side effects
Dizziness
somnolence
peripheral edema
weight gain
ocular effect
Gabapentin CrCL < 60 dose reduction
reduce dose or inc interval
Gabapentin used off-label for….
fibromyalgia
neuropathic pain
AUD
Pregabalin side effects
same as Gaba
dizziness
somnolence
peripheral edema/weight gain
mild anxiolytic
Pregabalin approved for use in…
fibromyalgia, PHN and neuropathic pain associated with diabetes and spinal cord injury
Muscle relaxants
Baclofen = Lioresal
Cyclobenzaprine = Flexeril
Tizanidine = Zanaflex
Muscle relaxant side effets
Dry mouth
excessive sedation, dizziness, confusion, muscle weakness
Tizanidine = Hypotension
