Pain & Opioids

Question 1

The detection and perception of noxious stimuli

Answer 1

Nociception

Question 2

Receptors for pain

Answer 2

Free nerve endings

Question 3

Entry of A-delta & C fibers into the _______

Answer 3

Posterior horn

Question 4

Where do cell bodies of A-delta and C fibers lie?

Answer 4

Dorsal root ganglia

Question 5

Occurs when transmission of pain through substantia gelatinosa is suppressed

Answer 5

Spinal analgesia

Question 6

Mu-2 is dominant receptor

Answer 6

Spinal analgesia

Question 7

After IV administration, opioids act on ___________ & _________ in spinal analgesia

Answer 7

Periventricular; periaquaductal gray

Question 8

Opioids act on limbic system, hypothalamus, and thalamus

Answer 8

Supraspinal analgesia

Question 9

Mu-1 is the dominant receptor

Answer 9

Supraspinal analgesia

Question 10

Interneurons release?

Answer 10

Enkephalin

Question 11

Which receptors do mixed agonist/antagonists use?

Answer 11

Kappa & delta

Question 12

Which receptors does morphine work on for spinal analgesia? Where?

Answer 12

Kappa; lamina I & II

Question 13

Which receptors does morphine work on for supraspinal analgesia

Answer 13

Mu-1

Question 14

How does morphine cause respiratory depression?

Answer 14

Decreases sensitivity to CO2

Question 15

Morphine c/i in?

Answer 15

Head injury d/t increased CSF pressure

Asthma d/t bronchoconstriction

Question 16

How does morphine affect neonates?

Answer 16

Crosses placenta causing resp depression and physical dependence

Question 17

Pharmacokinetics of morphine

Answer 17

Significant first-pass metabolism, use parenterally;
Rapid distribution, cross placental barrier;
Conjugated in liver to active metabolite;
Excreted in urine;
Prolong duration in epidural space (less lipid soluble)

Question 18

Morphine-6-glucuronide

Answer 18

Greater duration of action;
650 x analgesia than morphine;
Low permeability to BBB

Question 19

Meperidine works on which receptors?

Answer 19

Mu and kappa

Question 20

Methadone works on which receptors?

Answer 20

Mu

Question 21

Methadone causes resp depression ___ morphine

Answer 21

Less than

Question 22

Methadone uses

Answer 22

Control heroin withdrawal symptoms

Question 23

100x analgesic potency than morphine

Answer 23

Fentanyl

Question 24

Is fentanyl hydrophilic or lipophilic

Answer 24

Highly lipophilic

Question 25

A/E of fentanyl transdermal patch

Answer 25

Hypotension

Question 26

Fentanyl metabolized by

Answer 26

P450

Question 27

_______ is more potent than Fentanyl

Answer 27

Sufentanil

Question 28

Cough suppression Converts to morphine Much less analgesia than morphine Less euphoria/ abuse/ dependence

Answer 28

Codeine

Question 29

Drugs that stimulate one receptor but block another

Answer 29

Mixed agonist-antagonist

Question 30

Pentazocine works on which receptors?

Answer 30

Agonist on Kappa & weak antagonist on Mu & delta

Question 31

``` Moderate analgesia Less euphoria Resp depression in high doses Decreased GIT activity High dose = HTN, increased workload of heart Tolerance & dependence ```

Answer 31

Pentazocine

Question 32

Used in opioid detoxification | Less severe side effects in high dose

Answer 32

Buprenorphine

Question 33

Buprenorphine acts on ____ receptors

Answer 33

Mu

Question 34

Limited role as analgesic | Cause psychotic symptoms

Answer 34

Nalbuphine & Butorphanol

Question 35

Tramadol acts on ___ receptors

Answer 35

Mu

Question 36

Naloxone is a competitive antagonist of?

Answer 36

Mu, kappa, & delta receptors