Exam 4 - Opioids

Question 1

Endogenous Opioids

3 families and Receptors

Answer 1

BED

1) Beta
2) enkephalins
3) dynorphins

Question 2

Endogenous Opioids

Beta Receptor, Gene

Answer 2

• mu and delta receptor
• POMC gene
• pituitary
• gene related to ACTH, MSH

Question 3

Endogenous Opioids

Enkephalin Receptor, Gene

Answer 3

• delta and mu receptor
• pro-enkephalin gene
• brain, spine

Question 4

Endogenous Opioids

Dynorphine Rceptor, Gene

Answer 4

• kappa receptor
• pro-dynorphin gene
• brain, spinal cord

Question 5

Endogenous Opioids

Mu receptor effects

Answer 5

-analgesia, resp depression,

euphoria, dependence

Question 6

Endogenous Opioids

Delta receptor effects

Answer 6

-analgesia, otherwise unclear

Question 7

Endogenous Opioids

Kappa receptor effects

Answer 7

-spinal analgesia, sedation, endocrine,

dysphoria, psychotomimetic

Question 8

Endogenous Opioids

Non-opioid receptor

Answer 8

-DM: antitussive effects

Question 9

Opioids

Therapeutic effects

Answer 9

• analgeisa (not neuropathic)
• antitussive (not SOPD, emphysema)
• antidiarrheal (but constipation :( )
• acute Pulm Edema relief (but resp depress)
• good mood! (but don’t abuse it)

Question 10

Opioids

Analgesia

Answer 10

• not neuropathic (shingles)
• best for slow pain (C fiber)
• increase threshold/tolerance
• selective for pain
• inhibit ascending pathway (C fiber)
• activate supra-spinal descending inhibitory pathway (PAG
• pre-med anasthesia
• spinal anasthesis (local + fentanyl)

Question 11

Opioids

Antitussive

Answer 11

• not opioid receptor mediated
• DM receptors /(not stereoselective)
• dextro isomers only have antituss effects

Question 12

Opioids

Ant-diarrheal

Answer 12

• mu enteric receptors
• decrease peristalsis, secretions
• no long-term tolerance
• delays other drug absorption

Question 13

Opioids

Adverse effects

Answer 13

-constipation (use stool softeners)
-nausea/vomit (tx w/ ondansetron)
-sedation (dimishes w/ time)
-miosis (tx w/ atropine)
-pruritus from mast cell stim
LESS COMMON
-urinary retention
-resp depression
-CV effects, truncal rigidity, dysphoria, addiction

Question 14

Opioids

OD triad

Answer 14

1) pinpoint pupils
2) resp depression
3) coma

Question 15

Opioids

Tolerance

Answer 15

• after 2 weeks of use
• w/ high/fx dosing
• cross-tolerance between opioids
• therapeutic index unchanged
• constipation and miosis unchanged

Question 16

Opioids

equi-analgesia

Answer 16

-same potency across class

Question 17

Opioids

Contraindications

Answer 17

• head injury, preg,
• pulm/renal/hepatic dysfx’n
• Addison’s/hypothyroidism
• abuse hx
• drug interactions

Question 18

Opioids

Drg Interactions

Answer 18

-MAOIs w/ meperidine, propoxyphene
(causinbg serotonin syndrome)
-sedative hypnotics and antipsychotics
(causing resp depression)

Question 19

Opioids

Routes

Answer 19

oral, buccal, sublingual, transdermal,

nasal, suppository, parenteral

Question 20

Opioids

ADME

Answer 20

• liver 1st pass (morphine high, methadone low)

- higher oral dose than IV

Question 21

Opioids

High efficacy

Answer 21

1) morphine, methadone, fentanyl

2) meperidine, (heroin)

Question 22

Opioids

Morphine

Answer 22

• high 1st pass (25% avail)
• IV more potent
• don’t crush ‘em!
• glucuronidation to M6G (full) and M3G (partial)
• crosses BBB
• M3G no analgesia, causes seizures

Question 23

Opioids

Fentanyl

Answer 23

-1st line high efficacy class
-compared to morphine: more potent, lipophilic,
short-acting
-chronic pain patch, breakthrough pain lozenge
-epidural for preggos
-primary anesthesia for CV surg

Question 24

Opioids

Methadone

Answer 24

-1st line high efficacy class
-lower first pass, high bioavailability,
long half-life
-tx heroin addiction
-analgesia
-no histamine release
-blocks K channel -> long QT syn

Question 25

Opioids | Meperidine

Answer 25

- 2nd line high efficacy class - less potent, faster acting than morph - demethylation to normeperdine - normeperidine can have fatal CNS effects, seizure - tachycardia, mydriasis; no miosis

Question 26

Opioids | Heroin

Answer 26

- 2nd line high efficacy class | - pro-drug w/ rapid conversion

Question 27

Opioids | low/med efficacy

Answer 27

-usuall combo'd w/ aspirin/ibu Codeine Oxycodone

Question 28

Opioids | Codeine

Answer 28

- demethylation by CYP2D6 - poor and ultra metabolizers - higher antitussive effects - high histamine effects

Question 29

Opioids | Oxycodone

Answer 29

- highest low/med efficacy - CYP2D6 - slow release preparations available - hilbilly heroin (crush to abuse)

Question 30

Opioids | mixed/other

Answer 30

-agonism at kappa (analgesia); anatagonism at mu -side effects: dysphora, hallucinations pentazocine, tramadol, buprenorphine

Question 31

Opioids | Pentazocine

Answer 31

- high kappa agonism, low mu antagonism - parenteral site necrosis; use orally - combo w/ acetominophen

Question 32

Opioids | Tramadol

Answer 32

- Weak mu agonist - inhibits NE and 5HT reuptake, blocks NMDA receptors - mod pain tx - risk seizures - avoid MAOIs

Question 33

Opioids | Buprenorphine

Answer 33

- partial mu agonism, kappa antagonism - sublingual to avoid 1st pass - opioid dependence tx - combo with naxolone to prevent IV abuse

Question 34

Opioids | Anatagonist

Answer 34

- naxolone - competes w/ all opioid receptors (not DM) - tx for opioid overdose

Question 35

Opioids | non-analgesics

Answer 35

dextromethorphan, loperamide

Question 36

Opioids | dextromethorphan

Answer 36

- antitussive | - only active at DM receptors

Question 37

Opioids | loperamide

Answer 37

- no BBB pen | - Imodium AD antidiarrheal

Question 38

Pain Mgmt | 3 steps

Answer 38

MILD: ASA/APAP/NSAIDs MOD: combo ASA/APAP/NSAID w/ low/med efficacy SEVERE: high eff opioid w/ or w/o adjuncts