Ch 11 - Pain Medicine: Opioid Pharmacology

Question 1

What are the presynaptic actions of opioids?

Answer 1

Lower influx of Ca to reduce NT release in sensory C fibers

Question 2

What are the postsynaptic actions of opioids?

Answer 2

Inc the transport of K in the cell to facilitate hyperpolarization in 2nd order neurons

Question 3

Opiates activate the chemoreceptor trigger zone in the medulla, which leads to ____.

Answer 3

GI SE of nausea and vomiting

Question 4

Opioid receptor type Mu1 causes

Answer 4

Analgesia

Question 5

Opioid receptor type Mu2 causes

Answer 5

Respiratory depression 
Sedation
Vomiting
Euphoria
Anorexia
Physical dependence
Pruritus

Question 6

Opioid receptor type Delta causes

Answer 6

Analgesia

Spinal analgesia

Question 7

Opioid receptor type Kappa causes

Answer 7

Analgesia
Sedation
Psychomimetic effects
Dyspnea
Respiratory depression
Euphoria
Dysphoria

Question 8

Lipid-soluble drugs exert most of their effect at ___.

Answer 8

Localized areas where they are administered

ex) fentanyl

Question 9

What are the endogenous opioids?

Answer 9

Leu-Enkephalin
Beta-Endorphin
Dynorphin A&B

Question 10

What are the opioid agonists?

Answer 10

Morphine
Diamorphine (heroin)
Fentanyl
Meperidine
Methadone

Question 11

What are the opioid antagonists?

Answer 11

Naloxone

Naltrexone

Question 12

What are the partial opioid agonists?

Answer 12

Buprenorphine

Pentazocine

Question 13

MOA of oxycodone

Answer 13

Mu agonist

Question 14

Metobalites of Oxycodone

Answer 14

Oxymorphone

Noroxycodone

Question 15

MOA of Oxymorphone

Answer 15

Opioid agonist

Question 16

Metabolites of Oxymorphone

Answer 16

6-Hydroxy-oxymorphone

Question 17

MOA of Hydromorphone

Answer 17

Mu agonist

Question 18

Metabolites of Hydromorphone

Answer 18

Hydromorphone-3-Glucuronide

Question 19

MOA of Tramadol

Answer 19

Weak Mu agonist

Weak NE/5HT reuptake inhibitor

Question 20

Contraindication for Tramadol

Answer 20

CI with MAOI or SSRI d/t serotonin syndrome

Question 21

MOA of Morphine

Answer 21

Mu agnoist

Question 22

Metabolites for Morphine

Answer 22

Morphine-3-glucuronide
Morphine-6-glucuronide
Hydromorphone

Question 23

Contraindication for Morphine

Answer 23

Do not use in renal failure

Question 24

MOA of Meperidine

Answer 24

Weak mu agonist

Question 25

Metabolites of Meperidine

Answer 25

Normeperidine

Question 26

Contraindication for Meperidine

Answer 26

Do not administer with MAOI

Question 27

MOA of Hydrocodone

Answer 27

Mu and kappa agonist

Question 28

Metabolites of Hydrocodone

Answer 28

Dihydrocodeine | Hydromorphone

Question 29

MOA of Methadone

Answer 29

Mu and delta agonist NE and 5HT reuptake inhibitor NMDA antagonist

Question 30

Metabolites of Methadone

Answer 30

2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) (inactive)

Question 31

Contraindication for Methadone

Answer 31

May cause QT | prolongation

Question 32

MOA of Fentanyl

Answer 32

Mu agonist

Question 33

Metabolites of Fentanyl

Answer 33

Norfentanyl

Question 34

MOA of Buprenorphine (Subutex or Suboxone)

Answer 34

``` Partial mu and kappa agonist, delta antagonist Suboxone contains naloxone (receptor antagonist) ```

Question 35

MOA of Pentazocine (Talwin)

Answer 35

Kappa agonist, mu antagonist

Question 36

MOA of Butorphanol (Stadol)

Answer 36

Kappa agonist, mu antagonist

Question 37

MOA of Nalbuphine (Nubain)

Answer 37

Kappa agonist, mu antagonist

Question 38

How can opioids cause respiratory sedation?

Answer 38

Acts on brainstem to reduce sensitivity of the respiratory centers to PCO2

Question 39

How can opioids suppress coughing?

Answer 39

Inhibitory effect on the brainstem nuclei in the cough reflex pathway (common use for codeine)

Question 40

How do opioids cause constipation?

Answer 40

Maintained contraction of the smooth muscles in the gut (and therefore decreased motility)

Question 41

How do opioids cause sexual dysfunction?

Answer 41

Correlated to hypogonadism and associated with lower testosterone levels (erectile dysfunction, decreased libido)