Opioids and Agonists

Question 1

Fentanyl Class

Answer 1

Opioid agonist

Question 2

Fentanyl Use

Answer 2

reduce pain and anxiety, decrease somatic and autonomic responses, less inhaled anesthetic agent required, and postop analgesia

Question 3

Fentanyl MOA

Answer 3

Binds to Mu1, Mu2, Kappa, and delta receptors
Decrease neurotransmitter release by increasing potassium efflux and MARK cascade and decreasing adenyl cyclase production and calcium influx of ascending and descending pain pathways

Question 4

Fentanyl Dose

Answer 4

Induction dose as adjunct: 1 – 3 mcg/kg
Infusion: 0.01 – 0.05 mcg/kg/min
Small dose boluses: 25 – 50 mcg

Question 5

Fentanyl Pharmacokinetics

Answer 5

Onset: 2 – 5 minutes
Peak effect: 20 – 30 minutes
DOA: 0.5 – 1 hours
Redistribution
Extensive uptake in lungs and red blood cells → cough
- Metabolism = Hepatic metabolism to inactive metabolite norfentanyl
- Excretion = Eliminated in feces and urine

Question 6

Fentanyl Contraindications

Answer 6

Respiratory depression or obstructive airway diseases
Liver disease
Known intolerance or hypersensitivity

Question 7

Fentanyl Considerations

Answer 7

• Pulmonary 1st pass can cause coughing
• Apnea before loss of consciousness
• Depresses respiratory reflexes
• Fentanyl transdermal patch: Once applied, it takes 11 hours for peak effect. Once removed, it takes 18 hours for plasma concentration to decrease by half

Question 8

Dilaudid Class

Answer 8

Opioid agonist

Question 9

Dilaudid Use

Answer 9

reduce pain and anxiety, decrease somatic and autonomic responses, less inhaled anesthetic agent required, and postop analgesia

Question 10

Dilaudid MOA

Answer 10

Primarily Mu agonist, some Kappa
Decrease neurotransmitter release by increasing potassium efflux and MARK cascade and decreasing adenyl cyclase production and calcium influx of ascending and descending pain pathways

Question 11

Dilaudid Dose

Answer 11

Small bolus’ 0.2mg

Question 12

Dilaudid Pharmacokinetics

Answer 12

- Onset = 15 - 30min 
       Peak = 30 - 90 min 
- DOA = 4 - 5 hours 
- Metabolism = hepatic via CYP system to hydromorphine-3-glucuronide (inactive) 
- Excretion = kidneys

Question 13

Dilaudid Contraindications

Answer 13

GI obstruction

Question 14

Dilaudid Considerations

Answer 14

Addictive

Question 15

Meperidine Class

Answer 15

Opioid agonist

Question 16

Meperidine Use

Answer 16

reduce pain and anxiety, decrease somatic and autonomic responses, less inhaled anesthetic agent required, postop analgesia, and shivering

Question 17

Meperidine MOA

Answer 17

Bind to Mu1, Mu2, and Kappa
Decrease neurotransmitter release by increasing potassium efflux and MARK cascade and decreasing adenyl cyclase production and calcium influx of ascending and descending pain pathways

Question 18

Meperidine Dose

Answer 18

IV small bolus’ 12.5-25mg

Question 19

Meperidine Pharmacokinetics

Answer 19

Onset = 5 min 
Peak 30 - 60 min 
DOA = 2 - 4 hours 
Metabolized = liver via CYP into normeperidine which lowers seizure threshold 
Eliminated = kidney

Question 20

Meperidine Contraindications

Answer 20

Kidney failure (build up of normeperidine)
Pt on MAO inhibitors
Seizures

Question 21

Meperidine Considerations

Answer 21

• Structurally like atropine and can cause tachycardia
• Demonstrates similarities to local anesthetics when administered intrathecally
• Significant drug interaction with MAO inhibitors (profound HTN)
• Decreases post op shivering because of kappa receptor effects
• Can cause histamine related bronchospasm

Question 22

Remifentanil Class

Answer 22

Opioid Agonist

Question 23

Remifentanil Use

Answer 23

Reduce pain, quick on/off great for intraop

Question 24

Remifentanil MOA

Answer 24

Bind to Mu1, Mu2, Kappa, and delta receptors
Decrease neurotransmitter release by increasing potassium efflux and MARK cascade and decreasing adenyl cyclase production and calcium influx of ascending and descending pain pathways

Question 25

Remifentanil Dose

Answer 25

IV induction 2 - 5 mcg/kg | IV gtt 0.05 - 0.25 mcg/kg/min

Question 26

Remifentanil Pharmacokinetics

Answer 26

``` Onset = 1 min Peak = 1 min DOA = 5 - 10 min Metabolism = ester hydrolysis via blood and tissue esterases Elimination = kidneys ```

Question 27

Remifentanil Contraindications

Answer 27

Not for epidural or spinal anesthesia

Question 28

Remifentanil Considerations

Answer 28

- Induction doses of reminfentanil may cause profound bradycardia and are often administered with ephedrine - Remifentanil’s metabolism by plasma esterases (not pseudocholinesterases) lend itself well to patients with renal and/or liver failure - Remifentanil’s rapid onset, short DOA and titratability lend itself well to an intraoperative infusion - Remifentanil in may contribute to post-operative hyperalgesia, therefor the CRNA should create a plan for postoperative analgesia

Question 29

Nalaxone Class

Answer 29

Nonselective opioid antagonist

Question 30

Nalaxone Use

Answer 30

Reversal of opioids and alcohol use disorder

Question 31

Nalaxone MOA

Answer 31

Competitively inhibits opioid receptors and reverses opioid induced respiratory depression, analgesia, sedation, nausea, pruritus, and constipation by displacing the opiate from mu receptors

Question 32

Nalaxone Dose

Answer 32

40mcg bolus’ slowly

Question 33

Nalaxone Pharmacokinetics

Answer 33

Onset = 1 min DOA = 30 min (shorter than opioids) Metabolism: liver Excretion: kidneys

Question 34

Nalaxone Contraindications

Answer 34

Hypersensitivity | Acute opioid withdrawal

Question 35

Nalaxone Considerations

Answer 35

Side effects = pulmonary edema, tachycardia, hypertension, n/v Caution with liver impairments and renal failure

Question 36

Flumazenil Class

Answer 36

Benzodiazepine competitive antagonist

Question 37

Flumazenil Use

Answer 37

Reverse benzo affects

Question 38

Flumazenil MOA

Answer 38

Competitive antagonist of GABA receptors, blocking or reversing benzos effects

Question 39

Flumazenil Dose

Answer 39

0.2mg IV, titrate in 0.1mg increments to prevent rebound effects

Question 40

Flumazenil Pharmacokinetics

Answer 40

``` Onset = 1 - 3 min DOA = 3 - 30 min Metabolism = microsomal enzymes in liver Elimination = kidneys ```

Question 41

Flumazenil Contraindications

Answer 41

Caution with chronic benzodiazepine use, may cause acute withdrawal Avoid with seizure patients on antiepileptics

Question 42

Flumazenil Considerations

Answer 42

Short half life, risk for rebound effects