Opioids

Question 1

Clinical observations in pts with morphine tolerance d/t prolonged use (physiological effects unchanged by tolerance)

Answer 1

miosis (pinpoint pupils)

constipation

**tolerance does not develop to the above clinical effects

Question 2

Morphine is safe for use in asthmatics

True or False

Answer 2

False.

Morphine can cause bronchoconstriction and respiratory depression

Question 3

effects of morphine on respiration

Answer 3

↓ Rate

↓ volume

↓ tidal exchange

CNS becomes less responsive to pCO1. Irregular breathing. Apnea. Build up of CO2

Question 4

morphine can cause kappa opioid receptor to stimulate which cranial nerve causing what physiological effect ?

Answer 4

CNIII (Edinger-Westphal nucleus)

miosis

Question 5

The drug ______ partially blocks kappa receptor reversing miosis

Answer 5

atropine

Question 6

cardiovascular effects of morphine

Answer 6

vasodilation –> hypotension

Question 7

GI effects of morphine

Answer 7

constipation

↓ HCl secretion

Question 8

Effects of morphine on smooth muscle

Answer 8

biliary - ↑ pressure

bladder - ↑ detrusor muscle tone / urinary urgency / urinary retention

bronchioles - bronchoconstriction
*contraindication for asthmatics

uterus - contraction of uterus can prolong labor

Question 9

Naloxone

Answer 9

displaces morphine from all receptors / immediate onset (3-5imn) / short duration (30-45min)

Question 10

S/S morphine toxicity

Answer 10

respiratory depression

miosis

coma

Question 11

Tx of morphine toxicity

Answer 11

ventilation

opioid antagonist (naloxone)

Question 12

Contraindications for morphine

Answer 12

acute respiratory depression

renal failure (d/t morphine-3 and morphine-6-glucuronide metabolite accumulation

chemical toxicity

↑ intracranial pressure, head injury

biliary colic

Question 13

potentiation

Answer 13

additive depression observed with coadministration of CNS depressants + OPIOID

Question 14

buprenorphine

Answer 14

used in conjunction with methadone for detoxification / short and long term

mixed agonist-antagonist action

Question 15

Diphenoxylate

Answer 15

therapeutic use: anti-diarrheal drug

little analgesic effect

similar to meperidine

Question 16

methadone

Answer 16

similar potency to morphine

long duration = 16-20hrs

used in narcotic maintenance tx

Question 17

meperidine

Answer 17

same potency as morphine

toxicity similar to atropine (dry mouth, dry as a bone, blind as a bat, red as a beet, mad as a hatter)

Question 18

Fentanyl

Answer 18

synthetic

80-100X the potency of morphine

short onset (5 min) and duration (30-45min)

used as pre-op med

“china white”

Question 19

Hydromorphone (Dilauded)

Answer 19

9X potency of morphine

less constipation
no miosis

ketone at 6 hydroxyl position of morphine

Question 20

Heroin

Answer 20

derived from resin of poppy plant

“Lady, white girl, horse, black tar, brown sugar, smack, goods, H, junk, harry, beast”

crosses BBB rapidly (vs. morphine) and is hydrolyzed to morphine making more of the drug in the brain –> 3-4X more potent than morphine

Question 21

Heroin

Answer 21

derived from resin of poppy plant

“Lady, white girl, horse, black tar, brown sugar, smack, goods, H, junk, harry, beast”

crosses BBB rapidly (vs. morphine) and is hydrolyzed to morphine making more of the drug in the brain –> 3-4X more potent than morphine

most lipophilic opioid

acetyl groups at 3 and 6-hydroxyl positions (instead of hydroxyl)

Question 22

codeine

Answer 22

hydroxyl group replaces methyl group at 3 position

1/10 the potency of morphine

antitussive properties

withdrawl is relatively mild

Question 23

hydroxyzine

Answer 23

potentiates meperidine action

unlike morphine: less constipation
causes mydriasis (dilated pupils)

Question 24

Mu-1 receptor

Answer 24

Analgesia

enhance development of physical dependence

Question 25

Mu-2 receptor

Answer 25

respiratory depression

miosis

euphoria

physical dependence

reduced GI motility

Question 26

Mu receptor actions

Answer 26

P hysical dep.
E uphoria
A nalgesia
R esp. dep.

+ miosis
+ constipation

Question 27

Kappa receptor action

Answer 27

D ysphoria
A nalgesia (spine)
M iosis
I nhibition ADH
S edation

Question 28

3 Endogenous Opioid Peptides

Answer 28

enkephalins

endorphins

dynorphins

Question 29

Enkephalins

Answer 29

5 AA

met-5
leu-5

Question 30

what are the precursors to endogenous opioid peptides?

Answer 30

1. proenkephalin A

proenkephalin B

2. prodynorphin
3. propriomelanocortin (POMC)

Question 31

Endorphin

Answer 31

30 AA

POMC precursor

Question 32

Prodynorphin

Answer 32

dynorphin A & B

Question 33

Proenkephalin

Answer 33

met and leu enkephalin

Question 34

POMC

Answer 34

Beta-endorphins