Week 12-Analgesics Flashcards
What are the non-opioid analgesics?
NSAIDs
acetaminophen
What are the adjuvant analgesics?
anticonvulsants (gabapentin)
TCAs
SSRIs
SNRIs
What are the opiate analgesics?
codeine
morphine
What are the opioid analgesics?
propoxyphene tramadol hydromorphone oxycodone fentanyl meperidine methadone
What is the MOA of NSAIDs
inhibition of cyclooxygenase (COX)
*most are non selective for COX 1 and 2
COX 1 is _______
city protective
COX 2 is ______
inflammatory
What level of pain are NSAIDs given?
mild to moderate
What is the ceiling effect associated with NSAIDs?
addition drug gives no additional analgesia, only increased side effects
What are the NSAID class side effects? (4)
GI upset
GI irritation/ ulceration
edema
renal impairment
What are the non Opioid NSAID classes? (6)
salicylic acid derivative propionic acids acetic acids fenamates oxicame cox-2 inhibitors
what are the NSAID salicylic acid derivatives?
aspirin and salsalate
What are the NSAID propionic acids?
ibuprofen
ketoprofen
naproxen
What are the acetic acid NSAIDs?
keterolac
diclofenac
etodolac
indomethacin
What is a oxicam NSAID?
meloxicam
What is a COX 2 inhibitor NSAID?
Celecoxib (Celebrex)
If one NSAID fails then _____
try another
Why do NSAID combinations with dual MOAs work in synergy?
efficacy > sum of the individual components
What is dose tritiation of NSAID combinations limited by?
the non-opioid
often the cause of unintended overdose
most hepatic failures are from excessive opiate/ APAP use
What is the maximum dose of acetaminophen daily?
4 grams daily- soon to be 3g daily per FDA?
What is the maximum dose of aspirin?
4 grand daily but higher for anti-inflammatory
What is the maximum dose of ibuprofen?
3.2 grams daily
What NSAID is a weak anti-inflammatory agent and contraindicated with less than 16 years old?
salicylic acids- aspirin
What are salicylic acids (aspirin) contraindicated if less than 16 years of age?
Risk of Reyes Syndrome
What is the max daily dose of salicylic acid for anti-inflammatory?
3.6-5.4 grams daily
What NSAID is anti-inflammatory, anitypyretic and analgesic?
propionic acids-ibuprofen
What is the max dose of ibuprofen for fever/pain/dysmenorrhea?
max 1.2 grams daily
What is the only commonly available injectable NSAID used for moderate to severe pain?
keterolac (Toradol)
When is keterolac (Toradol) useful?
post- op pain
Why is keterolac (toradol) only used for 5 days?
increased risk of GI bleed
What is the usual dose of keterolac (toradol)?
30mg IVP q6h (max 120md/daily)
When should keterolac (toradol) dose be reduced to 15mg?
pts >65 years
body weight less than 50kg
“moderately” elevated serum creat (>2mg/dL)
What NSAID is for mild to moderate pain that is little used anymore?
fenamates-Mefenamic acid (Ponstel)
What NSAID should you avoid alcohol due to enhancing mucosal irritation?
fenamates-Mefenamic acid (Ponstel)
What NSAID is mainly used for acute & chronic RA and OA?
Oxicams- Piroxicam (Feldene) & Meloxicam
What is the advantage of oxicams?
long half life (45-50 hours)
allows daily dosing
When should the dose of oxicams be reduced?
with hepatic dysfunction
What is the only remaining selective COX 2 inhibitor?
celecoxib (Celebrex)
What COX- 2 inhibitor was “voluntarily” removed in 2004? why?
Rofecoxib (Vioxx) due to increased number of “cardiac events” AMIs
When is celecoxib (Celebrex), a selective COX 2 inhibitor useful?
in non-cardiac patients (orthopedics)
What is a NON NSAID, Non-opioid analgesic that is an antipyretic agents with little anti-inflammatory activity?
acetaminophen (Tylenol)
What is the result of acetaminophen overdose?
hepatic failure
avoid in pts with alcoholic liver disease
What is the MOA of acetaminophen?
inhibits both COX isoenzymes
What is the result of Acetaminophen’s COX inhibition being more pronounced in the brain?
inhibits hypothalamic heat-regulating center
explaining its anti-pyretic activity
What is the acetaminophen adjustment for renal impairment?
CrCl 10-50: administer every 6 hours
CrCl <10: administer every 8 hours
*metabolites accumulate
What is the injection form of acetaminophen?
Afirmed
100mg/100mL (post op x 4 doses)
What is the dose of Afirmed in adults/adolescent greater than 50kg?
1000mg every 6 hours
max 4 grams/daily
What is the dose of Afirmed in adults/adolescents less than 50kg?
15mg/kg every 6 hours OR 12.5mg/kg every 4 hours
max 75mg/kg/daily
What is the child dosing of acetaminophen?
10-15mg/kg/dose every 4-6 hours
MAX 5 doses a day
What is the treatment for acetaminophen toxicity?
N-acetylcysteine (Mucomyst) oral loading dose 140mg/kg
IV therapy: N-acetylcystine (Acetadote)
According to a study in Norway 114, 744 children born between 1999-2009 with history go long-term acetaminophen use during pregnancy was associated with what?
resulted in more than a 2 fold increase risk of offspring ADHD
What duration of acetaminophen use during pregnancy was associated with a decrease in ADHD use?
use for less than 8 days
According to JAMA study of single dose opioid vs non opioid for upper extremity pain in the ED what was the different among ibuprofen vs (oxycodone, hydrocodone and codeine)
No significant difference in pain scores 2 hours post dose.
What is the classic analgesic receptor?
mu
What is the basis of mixed agonist-antagonist agents?
opioid receptors
What is a natural agent from opium?
opiates
codeine and morphine
What are modifications of natural opiates or synthetics?
opioids
What are the mixed opioid agonist-antagonists?
buprenorphine
butorphanol
pentazocine
Nalbuphine (nubain)
What mixed opioid agonist-antagonists is still used?
Nalbuphine (nubain)
more effective in feamles
ceiling effect on respiratory depression
use in labor and delivery
What is “endogenous morphine” that is derived from small endogenous peptide hormones?
endorphins
What accounts for the variability of response to pain?
endorphins
What are the opiate/opioid side effects?
nausea itching sedation & cognitive impairment respiratory distress meiosis (pinpoint pupils) decreased GI peristalsis
What should be done for opiate/opioid decreased peristalsis?
constipation and impaction need to anticipate and prophylaxis!
tolerance does NOT develop
How can opioid induced constipation be prevented?
100mg of docusate sodium and 17.2mg of sennosides twice a day
OR
10mg biscadoyl at bedtime as needed if no BM in previous 24 hours; repeat in the morning if still no BM
What are the opioids for mild to moderate pain?
tramadol (ultram)
codeine (Tylenol #2-4)
Hydrocodone (Vicodin, lortab and Norco)
What is significant about tramadol (ultram)? (4)
weak opioid analgesic, useful for chronic pain
limit use for acute pain (increase dosage over weeks, increases N/V)
dual mechanism of action (weakly binds mu and inhibitors NE and serotonin reuptake)
useful for neuropathic pain
When was tramadol (ultram) reclassified as a controlled substance? (C-III)
in 2014, less abuse potential
What is a naturally occurring opiate with weak analgesic effects and an antitussive?
codeine
60 mg of codeine produces less analgesics than what?
650mg of aspirin
What metabolizes codeine to morphine?
CYP2D6
What CYP2D6 inhibitors decrease codeines effect?
antiemetic phenothiazines (thorazine, compazine and phenergen) haloperidol, fluoxetine and paroxetine
What percentage of the populations lacks the CYP2D6 enzyme?
10%
What medication if only available PO with acetaminophen C-III?
hydrocodone
Norco, lortab and Vicodin
What medication has better pain relief and longer duration compared to codeine?
hydrocodone
Hydrocodone is metabolized by _____ to ______.
CYP2D6; hydromorphone (Dilaudid)
What percentage of unintentional overdoses involve combination products, most commonly hydrocodone?
63%
What are the opioids for moderate to severe pain (C-II)?
morphine hydromorphone (dilaudid) oxycodone Meperidine Methadone Fentanyl
What is a prototype pure mu receptor agonist
morphine
What are the 2 active metabolites that are both really eliminated of morphine?
morphine-3-glucuronide (M3G) is a neurotoxin AND
M6G has analgesia 2-4x that of morphine
What is the result of morphine induced histamine release?
hypotension
pruritus
What medication has a significant first-pass effect? (concentration is greatly reduced before it reaches systemic circulation)?
morphine
What is the parenteral to oral dose ratio of morphine?
1:3
What is the infection dose of morphine sulfate?
2mg/mL
What are the dosage forms of morphine sulfate? (5)
injection immediate release (MSIR) SR Capsules (Kadian) CR tabs (MS Contin) Oral Solution (Roxanol)
What medication is 5-7x more potent than morphine that can result in iatrogenic overdoses?
hydromorphone (dilaudid)
What are the improved side effect profiles of hydromorphone (dilaudid)?
less histamine release
no active opioid metabolites (good in really impaired)
What is the recent sustained release product and dosages?
Exalgo
8, 12, 16, and 32mg CR tabs
What hydromorphone medication was recalled by the FDA for alcohol destroying the time release mechanism resulting in overdoses?
SR Palladone
What is the dosage form of hydromorphone (dilaudid) injection?
2mg/mL
What is more potent with fewer side effects than morphine?
oxycodone (oxycontin)
less histamine release, pruiritis and nausea)
Oxycodone is metabolized by _______ to _____.
CYP2D6; oxymorphone (also active)
When is oxycodone useful?
in patients with CYP2D6 deficiency or if on inhibitors (phenothiazine antiemetics, fluoxetine and paroxetine)
useful in non responders to codeine & hydrocodone
What are the dosage form of oxycodone?
oxycodone IR Roxicodone Oxycodone CR (OxyContin) with acetaminophen (Percocet) with aspirin (Percodan)
What is not recommended as a first line agent, more lipophilic and therefore has a more rapid onset with shorter duration of 2-3 hours?
Meperidine (Demerol)
What is Meperidine (Demerol) metabolized to?
active normeperidine (neurotoxic)
What is significant about the active normeperidine metabolite of Meperidine (demerol)?
long metabolite half life that accumulates
euphoria, irritability, delirium, tremors and seizures
toxicity is NOT reversed by opiate antagonists
metabolite is really eliminated
What is Meperidine (Demerol) contraindicated?
in patients on MAOIs (serotonin syndrome)
When can Meperidine (Demerol) be used according to American Pain Society (APS)?
in patients with serious opiate allergies
useful in controlling post anesthesia shivering
What medication has unique pharmacology-racemic mix of L & D isomers?
Methadone (Dolophine)
What does the L isomer of Methadone (Dolophine) do?
opioid activity
What does the D isomer of Methadone (Dolophine) do?
NMDA antagonist & NE/Serotonin reuptake inhibitor)
What can Methadone (Dolophine) also be useful for?
neuropathic pain
What medication has the longest & variable half life (12-190 hours; usually 24h)
Methadone (Dolophine)
What medication is useful entreatment of opiate addiction?
Methadone (Dolophine)
dosed every 24h
How long does analgesia last with Methadone (Dolophine)?
4-8 hours
therefore dose every 6-8 hours for analgesia
What medication is 100x more potent than morphine and is therefore dosed in mcg?
Fentanyl
What medication is extremely lipophilic, rapid onset and short duration of (30-60minutes)?
fentanyl
Why is Fentanyl a safe option in renal failure?
No active metabolites
What medication has fewer adverse effects than morphine or dilaudid with minimal histamine release and little hypotensive effect?
fentanyl
What are the dosage forms of fentanyl?
injection
lozenge (Actiq)
Transdermal (Duragesic)
What medication is not usually used in opiate naive patients?
Duragesic
What needs to monitor when giving duragesic?
respiratory rate for the first 24 hours
How often does Duragesic need to be replaced?
every 72 hours
DONT ADD
look for multiple patched when admitting out patients
When is fentanyl (Actiq and fentora) used?
only for long standing chronic (cancer) pain?
What medication is a pure mu receptor ANTAGONIST?
naloxone (narcan)
What medication if used to reverse sedation and respiratory depression and reverses analgesia?
naloxone (narcan)
What is the dose of naloxone?
dilute 0.4mg to less than 10mL saline (0.9%NaCl)
administer slow IVP (1ml every 1-2 minutes)
When should you stop administering naloxone?
monitor respiratory rate and stop when it increases
What is the first thing to be done with equianalgesic dosing?
convert all doses to oral morphine equivalents
What should be done for every 12 hour dosing?
Divide by 2
round down to SR
provide that dose as MS Contin every 12 hours ATC
What should be done for every 8 hour dosing?
divide by 3
round down to SR
provide that dose as MC contin every 8 hours around the clock
What can be done to provide “breakthrough” pain with equianalgesic dosing?
provide 20-25% (divided by 4 or 6) as IR every 4-6 hours PRN
What is the oral equiananalgesic dose of morphine 10mg parenteral?
30mg PO
What is the oral equianalgesic dose of hydromorphone 1.5mg parenteral?
7.5mg PO
What are the recommendations of the CBC Opioid-Prescribing Guidelines?
- nonpharmacologic therapy and non opioid are preferred for chronic pain
- When starting, prescribe immediate-release opioids
- Prescribe lowest effective dose
- For acute pain use the lowest effective IR dose for 3-7 days
- evaluate benefits and harm within 1-4 weeks of starting and again every 3 months or more frequently
- incorporate strategies to mitigate risk: offer naloxone for h/o of OD, SA, doses greater than 50MME per day or benzos
- Monitor controlled substance use with PDMP
- Urine D/S before staying new and annually
- avoid prescribing with Benzes
- Offer or arrange evidence-based treatment (MAT) for patients with opioid use disorder
How can you obtain morphine milligram equivalents (MME)?
multiple the total daily opioid dose by the conversion factor to obtain equivalent TTD of morphine in mg
What medications are used for medication assisted therapy (MAT)?
buprenorphine
naltexone
methadone
What MAT is a partial opioid antagonist to help with withdrawal symptoms that can be started with opioids in the pts system?
buprenorphine
What MAT is a opioid antagonist that may precipitate withdrawal symptoms that cannot be given unless opioid free for 7-14 days before use?
naltrexone
What is the IM form of naltrexone?
Vivitrol
What MAP is a long-acting opioid agonist that transfers opioid addiction to longer half-life allowing for a taper and therefore requires daily dosing ?
Methadone