Opiods

Question 1

σ Receptor

Answer 1

non-opioid receptor dysphoric effects

Question 2

μ Receptor

Answer 2

Opioid receptor

analgesia, euphoria, physical
dependence, bradycardia, GI, and
respiratory depression

Question 3

K (kappa) Receptor

Answer 3

mediates spinal analgesia, miosis, sedation, and diuresis

Question 4

General pharmacokinetics of opioids

Answer 4

well absorbed and rapidly distributed, highly lipophilic

exhibits first pass effect and has glucuronidated metabolites - morphine-6-glucoronide, normeperidine

renally excreted

Question 5

analgesic effects of opiods depend on the strength of the agonist

Answer 5

strong - morphine, methadone, heroin, meperidine, fentanyl

partial - pentazocine

mixed (agnoist and antagonist) - buprenorphine

weak - codiene, hydrocodone

Question 6

Cardiovascular and Respiratory effects of opiods

Answer 6

Vasodilation and orthostatic hypotension

Reduction of myocardinal oxygen demand and cardiac work

decrease PVR, preload, afterload and treats pulmonary edema

decrease sensitivity of the medulla to carbon dioxide

incresease intracranial pressure - contra with head innjury

Question 7

Gastrointestinal effects of opioids

Answer 7

constipation, mu receptors in the GI and a decrease in HCL secretion

constriction of spinchter of oddi and uriniary shpincter

prolonged labor - less seen in meperidine

emesis

encourage patient to take docusate, fiber and fluids,

Question 8

Opioid effects in the eye

Answer 8

parasympathetic - stimulation f the edinger-westphal nucleus of oculomotor nerve

There’s no tolerance in this effect - considered diagnostic

Question 9

General opioid effects (not respiratory, cardiac, eye or GI)

Answer 9

histamine release

increased prolactin release

inhibition of LH release

supress immunity

adjunct for anesthesia - sedation and analgesia

Question 10

adjunct opiods for anesthesia

Answer 10

alfentanil

sulfentanil

remifentanil

Question 11

opioids and preganacy

Answer 11

fetus/baby born with addiction and withdrawal symptoms - irritability, shrill crying, diarrhea and seizures

treat with diazepam, more severe withdrawal: camphorated tincture of opium or oral methadone

Question 12

opioid tolerance

Answer 12

happens with all of them

opioids can no longer enduce the endocytosis of the μ-opioid receptor (receptor recycling)

receptor uncoupling - dysfunction of structural interaction between the mu receptor and G proteins

need higher dose to reach same effects

miosis and constipation do not reach tolerance

Question 13

opioid withdrawal

Answer 13

6 to 12 hrs after last dose and ends within 72 hr

symptoms - Rhinorrhea, sweating, lacrimation,
chills, gooseflesh, yawning, anxiety, aggression, mydriasis

longer half life - longer withdrawal - methadone

Question 14

mechanism behind opioid addiction

Answer 14

bind in the nucleus accumbens,

release dopamine

Question 15

morphine

Answer 15

Opioid agonist - acts on all opioid receptors

used for moderate to severe pain, reduces dose needed for anesthetic and produces anxiolytic effect

vasodilation - MI

can cause respiratory depression which is fatal

not for use in head trauma patients

intense sedation and respiratory depression when used with other sedatives, alcohol or barbituates.

Question 16

codiene

Answer 16

Opioid agonist

Mild-moderate pain; metabolized to morphine

Combined with non-opioids to relieve pain

antitussive - cough suppressant

CYP2D6 metabolism

Question 17

meperidine

Answer 17

Opioid agonist

Rapid onset-short duration of action

Normeperidine (metabolite) can induce CNS stimulation

interacts with MOIs - hyperrexia c oma

strong antimuscarinic - less effect on smooth muscle

Good for use in pregnancy

Question 18

serotonin syndrome

Answer 18

SSRIs, TCAs, meperidine, dextromethorphan,
St. John’s Wort, linezolid, “triptans”

Symptoms: rigidity, hyperthermia, myclonus,
delirium, hypertension, tachycardia within 24
hrs

Treatment: Benzodiazepines, cyproheptadine,
ventilation

Question 19

diphenoxylate

Answer 19

Opioid agonist

Antidiarrheal

when combined with atropine reduces abuse potential

Loperamide - a deriviative that does not cross BBB

Question 20

fentanyl

Answer 20

Opioid agonist

100x more potent than morphine - given as a transdermal patch or transmucosal

highly lipophilic

short acting?

lozenges exist and are used to induce anesthesia in children

contraindication in pregnancy

Question 21

levorphanol

Answer 21

Opioid agonist

L-isomer of morphine

used to treat moderate to severe pain

The D-isomer Dextromethorphan; is not addictive and a cough suppressant

Question 22

methadone

Answer 22

Opioid agonist - better bioavialability and longer duration than morphine

treats heroin addication and moderate to severe pain

antagonist at NMDA receptor

Question 23

heroin

Answer 23

opioid agonist - shcedule I

injected and snorted

chronic injection leads to collapse of vessels

drug is highly lipophilic and metabolized to morphine

use during pregnancy leads to a newborn addicted to heroin and with withdrawal

uses have an increased incidence of HIV and hepatitis

oxycotin had a heroin like effect when crushed and snorted.

Question 24

tramadol

Answer 24

μ receptor agonist and reuptake inhibitor of NE and 5HT3

miminal opoid toxicities and used for chronic pain - neuropathic

typically combined with acetometaphen

Tapentadol - same but no effect at serotonin

Question 25

methylnaltrexone

Answer 25

Treats opioid-induced constipation

Does not cross BBB - the compound is methylated

Question 26

mixed - agonist and antagonist

Answer 26

pentazocine, Butorphanol, Nalbuphine

more affinity for Kappa receptor - retains analgesic effects with less addiction potential

less physical dependence and respiratory depression

psychomimetic effect - pentazocine (kappa)

precipitates withdrawal - decreases effect of full agonists

Question 27

Buprenorphine

Answer 27

partial mu agonist and at higher doses is an antagonist

kappa receptor blockage

given sublinguil, transdermal and parenteral

similar toxicities to morphine

treats opioid dependence

precipitates withdrawal - decreases effect of full agonists

Question 28

Naloxone/Naltrexone

Answer 28

opioid antagonist

Naloxone: IV; fast onset for opioid overdose
(1-3 min). Rapid offset. Repeated
administration until opioid is cleared.

approved for use in addicted newborns

Naltrexone - oral with long duration, used for maintenance therapy. Also reduces alcohol cravings

Question 29

opioid abuse

Answer 29

heroin is most abused - euphoria followed by sedation

rapid tolerance and dependence

MOA at mu and kappa receptors (agonists)

overdose - IV naloxone and ventilation

symptoms - everything is down - stupor, bradycardia, decreased respiration and miosis

withdrawal - methadone or beprenorphine

symptoms of withdrawal - lacrimation, rhinorrhea, yawning, sweating, gooseflesh, tremors

Question 30

schedule I opiods

Answer 30

Heroin

also Sch 1 - LSD, PCP

no medical use - high addiction

Question 31

schedule II opiods

Answer 31

morphine

also, cocaine and amphetamine

medical uses - high addiction

Question 32

schedule III drugs

Answer 32

barbiturates, anabolic steroids

medical use, moderate addiction potential