Opioid Analgesics And Antagonists

Front 1

what are the two classes of endogenous opioid peptides

Back 1

-endorphins
-enkephalins

Front 2

effects of endorphins

Back 2

-modifies or inhibits pain impulses (raises the threshold for pain perception)
-modifies the psychologic aspects of pain (diminishes discomfort)
-overall effect is to alter the perception of pain and increase pain tolerance

Front 3

effects of enkephalins

Back 3

-inhibit transmission of painful stimuli
-primary action as neurotransmitters released from spinal cord interneurons
-causes inhibition of subsequent release of substance P

Front 4

3 major types of opiate receptors

Back 4

-mu (mu1 and mu2)
-kappa
-sigma

Front 5

stimulation of following receptors cause?::
1. mu1
2. mu2
3. kappa

Back 5

1. supraspinal analgesia, euphoria
2. spinal analgesia
3. spinal analgesia

Front 6

effects produced by opioids at sigma receptors (dysphoria, psychotominesis) are not __________

Back 6

reversed by naloxone

Front 7

physical dependence is significant at the ________ receptors

Back 7

mu receptors

Front 8

high degrees of tolerance develop to what opioid effects?

Back 8

-analgesia, euphoria/dysphoria, sedation, respiratory depression, N/V, cough suppression

Front 9

minimal or no tolerance develops to what opioid effects?

Back 9

miosis, constipation, opioid antagonism

Front 10

what is necessary to avoid emergence of the characteristic abstinence syndrome?

Back 10

-continued dosing

Front 11

CNS effects of opioids

Back 11

-analgesia
-sedation
-respiratory depression

Front 12

analgesic effects of opioids

Back 12

-changes both pain perception (by raising the pain threshold) and the rxn to pain to increase pain tolerance

Front 13

interaction of opioids and other CNS depressants may result in?

Back 13

profound sedation and medullary depression

Front 14

respiratory depression effects of opioids

Back 14

-decreased ventilatory response to CO2; dose related depression of the medullary respiratory center
-results in slow, shallow, irregular breathing
-causes CO2 retention which dilates the cerebral vessels, resulting in increased ICP
-decreased sensitivity to CO2

Front 15

How can opioid-induced respiratory depression worsen head injury or COPD?

Back 15

-increased ICP from CO2 retention can worsen head injury
-decreased sensitivity of respiratory center to CO2 can be fatal for pts with COPD

Front 16

antitussive effect of opioids

Back 16

-suppression of the cough reflex through depression of the medullary coughing center (tolerance develops)
-dextarotary isomers are antitussive, but have no analgesic effects

Front 17

MOA of miosis from opioid use

Back 17

-excitatory action of opioids on the parasympathetic nerves to the pupil
-pinpoint pupils

Front 18

mechanism of opioids causing emesis

Back 18

-stimulation of dopamine receptors in the chemoreceptor trigger zone (CTZ) in the 4th ventricle (outside the BBB)
-activation of the medullary vomiting center (N/V)

Front 19

_____ may occur in 15-30% of CA pts receiving morphine for chronic pain; may require ___________

Back 19

1. chronic nausea
2. antiemetics

Front 20

CV effects of opioids

Back 20

-bradycardia may occur at higher doses
-due to stimulation of medullary vagolytic drug, (ex:atropine)

Front 21

CV effects are not usually observed with ___________ which has anticholinergic actions

Back 21

meperidine

Front 22

GI effects of opioid use

Back 22

-constipation (can be used to tx diarrhea)
-paralytic ileus (when given post-op may greatly intensify and prolong duration of ileus)

Front 23

what must be done as treatment for constipation with chronic opioid use?

Back 23

-stimulant laxatives and stool softeners (never as monotherapy)

Front 24

what are the effects of morphine use on labor and delivery?

Back 24

-morphine depresses uterine contractions, prolongs labor, and antagonizes the effects of oxytocics

Front 25

which opiate is preferred for obstetrical applications since it tends to increase uterine contractions?

Back 25

meperidine

Front 26

opioid effects on neonatals

Back 26

-crosses placenta and enters neonate's incompletely developed BBB causing neonatal respiratory depression
-reversible with neonatal formulation of naloxone

Front 27

compare differences in effects on neonates with morphine vs. meperidine

Back 27

-morphine has greater depressant effect; nl dose for mom can cause respiratory depression in neonate
-meperidine has higher lipid solubility; it distributes into mom's tissues, taking more time to enter neonate
-administering meperidine close to time of delivery helps to minimize neonatal effects

Front 28

full agonists for opioid analgesia
1. MOA
2. drugs (4)

Back 28

1. agonists at mu rec. for mod->severe pain
2. morphine, meperidine, methadone, fentanyl

Front 29

lower potency full agonists for opioid analgesia
1. MOA
2. drugs (3)

Back 29

1. agonists at mu rec. at lower doses for tx of mild->mod pain
2. codeine, hydrocodone, propoxyphene

Front 30

partial agonists for opioid analgesia
1. MOA
2. drugs (1)
3. efficacy

Back 30

1. partial agonist activity at the mu rec.
2. buprenorphine
3. limited due to dose-related ceiling effect

Front 31

mixed agonist-antagonists for opioid analgesia
1. MOA
2. drug (1)
3. efficacy

Back 31

1. antagonists at the mu rec/ agonists at the kappa rec
2. pentazocine
3. limited due to dose-related ceiling effect

Front 32

antagonists for opioid analgesia
1. MOA
2. drugs (2)

Back 32

1. antagonists at mu, delta, and kappa rec
2. naloxone, naltrexone

Front 33

comparison of parenteral vs oral admin of opioids

Back 33

-parenteral has faster onset, shorter duration (typically dosed q 4hrs)
-oral has delayed onset, longer duration (1st pass effecct may require higher doses)

Front 34

what are some considerations for dosing of opioids?

Back 34

-route conversions required
-drug conversions required
-dosages must be individualized
-parenteral vs oral routes

Front 35

what are the considerations when treating CA pt pain with opioids?

Back 35

-ever-increasing doses must be used as pt becomes tolerant
-physical dependence is not an issue
-regularly scheduled doses are more effective than PRN dosing

Front 36

clinical uses of opioids

Back 36

1. analgesia
2. acute pulmonary edema (relief of dyspnea)
3. cough (much lower doses than those for analgesia)
4. diarrhea

Front 37

opiate indications for pain
1. morphine, meperidine, and methadone
2. codeine
3.transdermal fentanyl

Back 37

1. relief of mod->severe acute and chronic pain
2. relief of mild->mod pain
3. management of chronic pain

Front 38

opiates for the following indications:
1. coughing
2. detoxification
3. management of opiate dependence

Back 38

1. codeine
2. methadone
3. methadone, buprenorphine

Front 39

what is an unlabeled use for morphine?

Back 39

-dyspnea associated with acute LV failure and pulmonary edema

Front 40

what are some contraindications for opioid use?

Back 40

1. combo of full agonist with a partial agonist or a mixed agonist/antagonist produces W/D syndrome
2. head injuries (in presence of increased ICP can cause lethal alterations to brain fx)
3. impaired pulmonary fx (COPD)

Front 41

what is the triad of opioid poisoning?

Back 41

-coma
-pinpoint pupils
-respiratory depression

Front 42

DI of opioids with other CNS depressants?

Back 42

-synergistic/additive effects

Front 43

1. DI of opioids with MAOI?
2. which opiate has highest ?incidence of DI with MAOI

Back 43

1. all opioids contraindicated due to higher incidence of hyperpyrexia, coma, and HTN
2. highest incidence with meperidine

Front 44

cross-tolerance occurs between all the opioid full agonists with respect to ?

Back 44

-analgetic, euphoriant, sedative, and respiratory efects

Front 45

tolerance to mixed agonist-antagonist opioids does not usually include____________

Back 45

-cross-tolerance to full agonists
(admin of mixed opioid to pt physically dependent on full agonist will cause W/D symptoms)

Front 46

what are the symptoms of physical dependence abstinence syndrome?

Back 46

mostly due to sympathetic overstimulation::
-piloerection, diarrhea, rhinnorhea
-mydriasis
-absence of seizure activity (usually does not result in life-threatening events)

Front 47

effects of withdrawal from methadone

Back 47

-less intense immediate syndrome; several days required to reach peak
-may last 2 wks; much milder symptoms compared to morphine and heroin