Unit 5: Pharm 2 Opioids & Non-opioids

Question 1

Explain Opioid R mech of action

Answer 1

G protein activated
adenylate cyclase inhibitted
decreased cAMP
Ca conductance decreaes
K conductance incrases

Question 2

where are opioid receptors located?

Answer 2

Brain
spinal cord
peripheral

Question 3

endorphins precurssor?

Answer 3

pre-proopiomelanocortin

Question 4

enkephalins precurosr?

Answer 4

pre-enkelphalin

Question 5

Dynorphin precursor?

Answer 5

pre-dynorphin

Question 6

Mu opioid receptor effects

Answer 6

resp depression
brady cardia
sedation
euphoria
prolactin release
mild hypothermia
miosis
urniary retention
N/V ( ^billiary pressure and decrease peristalis)
pruritis

Question 7

delta opioid R effects

Answer 7

resp depression
urinary retention
pruritus

Question 8

Kappa opioid effects

Answer 8

diuresis
antishivering
resp depression ???
sedation
dysphoria
halllucinations
delirium
miosis

Question 9

CV effects of opioids?

Answer 9

bradycardia
minimal effects on BP in healthy pt
no effect on myocardial contractility, but myocardial depression can occur if combined with Nitrous

Question 10

which opioids release histamine?

Answer 10

morphine, meperidine, codeine

Question 11

how do opioids effect body temp?

Answer 11

resent hypothalamic temp set point > decreased core body temp.

Question 12

How is morphine different in women than men?

Answer 12

greater analgesic potency
slower onset
longer DOA
lower post op opioid consumption

Question 13

Name the naturally occuring opioids

Answer 13

Phenanthrene derivatives
morphine
codeine

Question 14

Name the semisynthetic opioids

Answer 14

Morphine derivatives: hydromorphone, heroin, nalonxone, naltexone

thebaine derivatives: oxycodone

Question 15

name the synthetic opiods

Answer 15

Piperidine: meperidine
phenylpiperdines: fentanyl, sufentanil, remifentanil, alfentanil
diphenlypropylamine: methadone

Question 16

describe opioid potency

Answer 16

Meperidine 100mg
Morphine 10mg
Hydromorphone 1.4mg
Alfentanil 1000mcg (1mg)
Remifentanil 100mcg
Fentanyl 100mcg
Sufentanil 10mcg

Question 17

Which opioids produce active metabolites?

Answer 17

morphine: morphine-3-glucuronide, morphine-6-glucuronide

meperidine: normeperidine

Hydromorphone: depends on what book you read, but some say hydromorphone-3-glucuronide

Question 18

How are opioids metabolized?

Answer 18

Hepatic biotransformation
Remi is the exception: plasma erythrocytes and tissue esterases.

Question 19

Explain more about metabolism of Remifentanil

Answer 19

unaffected by psuedocholinesterase deficiency

Very liphophilic, but becasue it is rapidly metabolized it behaves more like drug with small Vd.

Therefore, remi is always dose at lean body weight.

Question 20

Why does meperidien exhibit anticholinergic effects?

Answer 20

structarlly releated to atropine

Question 21

Why should you be careful with meperidine when patient is taking MAOIs?

Answer 21

meperidine is a weak serotonin reputake inhibitor, and therefore can cause serotonin syndrome.

Question 22

Explain opioids pKas

Answer 22

All are > 7.2

exception is alfentanil 6.5

Question 23

Why is the pKA of alfentanil important?

Answer 23

AT body pH 90% is non-ionized (can diffuse across BBB) and 10% is ionized.

So has a rapid onset of action

Question 24

Remifentanil maintenance infusion dosing

Answer 24

0.1-1.0mcg/kg/min

Question 25

What is the context sensitive half time of remifentanil?

Answer 25

4 min, regardless of infusion length.

Question 26

Why is LBW always used to calculate remifentanil infusion dose?

Answer 26

Because it is metabolized so quickly there is no time to be distributed to the body’s fat.

Question 27

How can OIH from remifentanil be prevented?

Answer 27

With Ketamine or magnesium sulfate.

Question 28

Why can’t remifentanil be used in neuraxial anesthesia?

Answer 28

It contains the preservative, glycine, which can casue skeletal muscle weakness.

Question 29

How does methadone decrease pain?

Answer 29

1. Mu receptor agonist
2. NMDA receptor antagonist
3. Inhibits reuptake of monoamines in the synaptic cleft.

Question 30

What is methadones duration of action?

Answer 30

3-6 hours
But chronic administration prolongs the DOA and the duration of its analgesic effects.