Opiods Flashcards
how is alfentanil supplied
500 mcg/mL
2mL vial
what are the principal uses of alfentanil
anesthetic induction
maintenance
monitored anesthesia care MAC
what is the MOA of alfentanil
Mu-1(supraspinal)
Mu-2(spinal)
receptor agonism
endogenous opioid ligand ekephalin’s receptor
delta
endogenous opioid ligand endorphin’s receptor
mu
endogenous opioid ligand dynorphin’s receptor
kappa
how do opiods work?
Mu-1(supraspinal)
Mu-2(spinal)
receptor agonism
inhibition of ascending transmission of nociceptive information from the spinal cord dorsal horn
activation of pain control circuits that descend from the midbrain, via rostram ventromedial medulla
to the spinal cord dorsal horn
mu-1 location
supraspinal
mu-2 location
spinal
mu-1 effects
euphoria miosis bradycardia hypothermia urinary retention
mu-2 effects
respiratory depression
constipation
physical dependence
potency order of opioids greatest to least
Sufentanil Remifentanil-Fentanil Alentanil hydromorphone Morphine Meperidine
“Susan/Robert Formed A Happy Monique
MARS least to greatest without fent and hydro”
Vd of alfentanil
0.4-1 L/kg in adults
1/2 life of alfentanil
90-111 minutes
context sensitive 1/2 life
metabolism of alfentanil
hepatic metabolism via CYP-450
Ndealklation
glucuronide formation
peak of alfentanil
1-3 min
onset of alfentanil
60 seconds
duration of alfentanil
20 min
dose dependent
contraindicaions/adverse rxn alfentanil
hypersensitivity
N/V
chest wall rigidity
physiologic effects of alfentanil
CNS depressoin
respiratory depression
protein binding % of alfentanil
92%
how does acidosis/alkalosis affect protein binding?
protein binding increases with alkalosis
decreases with acidosis
Varies purpose:
Incremental injection: alfentanil
5-15 mcg/kg q 5-20 minutes
Max 75 assisted vent required
Continuous Infusion alfentanil
50-75 mcg/kg induction/ maintenance 1-1.5 mcg/kg/min procedure dependent
Induction of Anesthesia: alfentanil
130-245 – maintenance 0.5-1.5 mcg/kg/min *reduce concentration of inhaled agents by 30-50 for first hour
MAC dose alfentanil
3-5 mcg/kg q 5-20 min OR 0.25-1 mcg/kg/min initial dose 3-8 TOTAL dose 3-40
how is sufentanil supplied
50 mcg/mL
100 mcg/2mL
250 mcg/5mL
MOA of sufentanil
Mu-1 and Mu-2 receptor agonism
Binds to opiod receptors throughouts CNS.
Opening K channels- inhibiting Ca++ channels
Increase pain threshold
Alters pain perception
Inhibit ascending pain pathways
Inhibition of catecholamine release- controls sympathetics response to surgical stress (up to 30 mg/kg)
trade name of sufentanil
sufenta
protein binding % of sufentanil
91-93%
1/2 life elimination of sufentanil
2-4 hr
1/2 Context Sensative of sufentanil
25 min 3 hour infusion
40 min 6 hour infusion
metabolism of sufentanil
CYP3A4
liver
small intestine
excretion of sufentanil
urine
first pass uptake of sufentanil- pulmonary %
60
peak of sufentanil
5 min
onset of sufentanil
10 seconds
duration of sufentanil
30-60 minutes
contraindications of sufenanil
chest wall rigidity
hypersensitivity
Premed: sufenta
2-5 mcg
Induction: w/60-70% N2O sufenta
1.5-2.5 mcg/kg/hr
High Dose Opiod: sufenta
1-30 mcg/kg induction & 1-2 mcg/kg/hr
Balanced Anes: sufenta
0.1-0.3 mcg/kg bolus w/0.005-0.015 mcg/kg/min infusion
TIVA: sufenta
0.25-2 mcg/kg, 2.5-10 mcg bolus, 0.5-1.5 mcg/kg/hr
Analgesia: sufenta
0.1-0.3 mcg/kg or 0.0015-0.01 mcg/kg/min infusion
MAC: sufenta
2.5-10 mcgbolus
trade name of remifentanil
Ultiva
MOA of remifentanil
binds to mu-opiod receptors within CNS
increases pain threshold
alters pain reception
inhibits asscending pain pathways
how is remifentanil supplied
1 mg
2 mg
5 mg
when reconstituted is 1mg/mL
% protein bound of remifentanil
70%
High Dose Opioid: remifentanl
1-3 mcg/kg/min infusion w/propofol 3 mg/kg/hr
Induction w/hypnotic: remifentanil
0.5-1 mcg/kg bolus 0.1-1 mcg/kg/min
Balanced: anesthesia remifentanil
0.1-1 mcg/kg/min
TIVA: remifentanil
1-2 mcg/kg, 0.1-1 mcg/kg bolus
Analgesia: remifentanil
0.05-0.25 mcg/kg/min
MAC remifentanil
12.5-25 mcgbolus or 0.01-0.2 mcg/kg/min infusion
1/2 life context sensitive remifentanil
0-5 minutes
no matter how long the infusion
half life elimination remifentanil
dose dependent
terminal 10-20
effective 3-20
metabolism remifentanil
rapid via blood and tissue esterases
excretion remifentanil
urine
peak remifentanil
1-3 min
onset remifentanil
60 seconds
duration remifentanil
10 min
contrainications/AE remifentanil
Hypersensitivity
chest wall rigidity
N/V
trade name fentanyl
duragesic
sublimaze
how is fentanyl supplied
100 mcg/2mL
250 mcg/5mL
500 mcg/10 mL
1000mcg/20mL
MOA of fentanyl
Binds to stereospecific receptors at many sites within the CNS
Relief of pain
Pre-operative medication
Adjunt to general or regional anesthesia
% first pass uptake by the lungs of fentanyl
75%
elimination half life fentanyl
2-4 hours
Context sensitive half time fentaynl
75 minutes
peak fentanyl
5 min
onset fentanyl
10 sec
duration fentanyl- post bolus
30-60 min for full recovery
contraindications/AE fentanyl
hypersensitivity
chest wall rigidity
Premed: fentanyl
25-50 mcg
High Dose Opiod Anes: fentanyl
25-50 mcg/kg induction dose with 0.5mcg/kg/min infusion
Induction w/hypnotic fentanyl
1/5-5 mcg/kg
Induction w/60-70% N2O: fentanyl
8-20 mcg/kg
TIVA: fentanyl
5-20 mcg/kg, 25-100 mcg bolus 2-10 mcg/kg/hr
Balanced:fentanyl
25-100 mcg bolus or 0.5-5 mcg/kg
Analgesia fentanyl
1-3 mcg/kg bolus or 0.01-0.05 mcg/kg/min
MAC: fentanyl
12.5-50 mcg bolus
IV infusion rate fentanyl
10mcg/mL concentration
trade name of naloxone
narcan
evzio
how is naloxone supplied
0.4 mg/mL
MOA naloxone
Non-specific opiod receptor competitive antagonist (mu, delta, kappa)
Pure opioid antagonist
Compete and displaces opioids at receptor sites
Greatest affinity for mu-receptor
use of naloxone
Reverses opioid effects: RD, overdose, dependence, prurities, relax sphincter of Oddi spasm, urinary retention
onset naloxone
2 minutes
duration of action naloxone
15-45 minutes OFTEN SHORTER THAN THE HALF LIFE OF THE OPIOID- REDOSE POTENTIAL HIGH
half life naloxone
0.5-1.5 hours
excretion of naloxone
Urine as metabolites- adjust dose for renal pt
metabolism naloxone
Primarily hepatic via glucuronidation
(inactive metabolites)
no dose adjustment with liver dz
A/E of naloxone
MANY
CV- HTN, V-tach/fib, hypotension, flushing, fever
CNS- agitation/coma/pain/seizure/restless/hallucination
GI- N/V/Diarrhea crams
NMS- aches, paresthesias, piloerection, tremorn weakness
PULM- Dysp, hypoxia, pulm edema,
MISC- diaphoresis, sweating, hot flash, shiver, yawn, injection site rsn
- withdrawal symptoms induction of sympathetic excess- catecholamines
abrubt reversal may cause acute N/V/sweat/tachy is given post op – seizures, htn, pulmonary edema and arrhythmias- caution
concerns with naloxone
Renarcotization
No need with remifentanyl gtts- just turn it off
Buprenorphine- need much larger dose 2-4 mg/hr because high affinity for opioid receptor
May have methyl or propylparabens in formulation
dilution how to &
dose for naloxone
0.4mg/10mL = 40 mcg/mL or 0.04 mg/mL = most common dose
IV push: naloxone
1st dose= naloxone 0.04-0.4mg
repeat for effect
Infusion for pruritis naloxone
= 0.25 mcg/kg/hour
IF no response at 0.8 mg consider?
total consider other causes of RD
Heroin overdose naloxone
0.4-2 mg/dose repeat 2-3 min for effect
order from most lipophilic to least lipophilic (hydrophilic) or opiods
She F’d All My Random House Mates
Sufentanil- lipophilic Fentanyl Altenanil Meperidine Remifentanil Hydromorphone Morphine- hydrophils
properties of lipophilic neuroaxial opioids
Rapid onset sort duration limited rostral spread good for PCA less side effects
properties of hydrophilic neuroaxial opioids
prolonged single dose analgesia cephalic spread- concern for 2nd RD 6-12 hours later slow onset long lasting thoracic analgesia with lumbar admin NOT good for PCA side effects
