Analgesics

Question 1

Order of pain transmission

Answer 1

1. Injury occurs (tissue damage, inflammation, infection, etc.(
2. Release of arachidonic acid OR autocoids (bradykinin, histamine)
3. (if arachidonic acid) Arachidonic acid creates prostaglandins under the action of COX
4. Either autocoids OR prostaglandins activate nociceptors
5. Neurotransmission through spinal cord (synapse with opioid receptors)
6. Neurotransmission to brain (cerebral cortex –> perception of pain and emotional reaction to pain)

Question 2

Examples of autocloids

Answer 2

histamine and bradykinin

Question 3

examples of excitatory neurotransmitters released from the pre-synaptic neuron in the gray matter

Answer 3

glutamate and substance P

Question 4

Endogenous opioids

Answer 4

endorphins
enkephalins
dynorphins

Question 5

How do presynaptic opioid receptors inhibit pain neurotransmission?

Answer 5

They block voltage dependent calcium channels, which blocks exocytosis of excitatory neurotransmitters

Question 6

How do postsynaptic opioid receptors block pain neurotransmission?

Answer 6

They open potassium channels which hyperpolarize membranes and block the formation of action potentials, essential for transmitting pain sensation

Question 7

Examples of opioid receptors

Answer 7

Mu (u1)
Mu (u2)
delta
kappa

Question 8

What do u1 receptors induce?

Answer 8

analgesia, euphoria and physical dependence

Question 9

what do u2 receptors induce?

Answer 9

sedation, bradycardia, and resp. depression

Question 10

what do delta receptors induce

Answer 10

spinal anesthesia and development of tolerance to opioids

Question 11

what do kappa receptors induce

Answer 11

spinal anesthesia, miosis, and sedation

Question 12

Non-opioid analgesics

Answer 12

NSAIDs:
ibuprofen
naproxen
aspirin
acetaminophen

Question 13

MOA of NSAIDs

Answer 13

COX inhibitors that prevent the production of prostaglandins

Question 14

Pharmacotoxicology of NSAIDs

Answer 14

Gastric irritation, spontaneous hemorrhaging, tinnitus; acetaminophen can cause liver failure in overdoses

Question 15

MOA of fentanyl

Answer 15

full opioid receptor agonist; 100x more potent than morphine and 50x more potent than heroin

Question 16

What is hydrocodone

Answer 16

the most widely prescribed drugs on the market and yet when given for the relief of pain, its dose and potential for addiction can be reduced when given with other medications

Question 17

MOA of methadone

Answer 17

a full opioid receptor agonist that is used in the treatment of opioid addiction because it is a long-acting opioid agonist that reduces the daily cycles of craving and withdrawals.

Question 18

MOA of codeine

Answer 18

a moderate to strong opioid receptor agonist that is used as an antitussive medication

Question 19

BOA of buprenorphine

Answer 19

A partial opioid receptor agonist that is used in the treatment of moderate to severe opioid use disorder and as an analgesic

Question 20

What is suboxone

Answer 20

A combination of buprenorphine and the opioid antagonist naloxone used in the treatment of opioid addiction

Question 21

What is naloxegol?

Answer 21

a medication used to treat constipation in pts on long-term opioid therapy; a mu receptor antagonist that does not pass the BBB

Question 22

Examples of opioid receptor antagonists

Answer 22

naltrexone (naloxone) and vivitrol

Question 23

what is vivitrol

Answer 23

a opioid receptor antagonist that is an injectable formula of naltrexone

Question 24

What is lofexidine

Answer 24

an alpha2 adrenergic receptor agonist, a non-opioid, that is used to alleviate the physical symptoms of heroin and other types of opioid withdrawal

Question 25

MOA of gabapentin

Answer 25

increases GABA levels in the CNS which inhibits the subunit in the voltage-dependent calcium channel, thus suppressing the release of glutamate

Question 26

Therapeutic use of gabapentin

Answer 26

treatment of diabetic peripheral neuropathy, trigeminal neuropathy, fibromyalgia, and "phantom limb pain"

Question 27

What type of anesthetic is procaine?

Answer 27

ester-type anesthetic

Question 28

what type of anesthetic is lidocaine?

Answer 28

amide-type anesthetic

Question 29

What is the difference between ester-type and amide-type anesthetics?

Answer 29

the half life; amide-type anesthetic half life is typically 10 min and ester-type anesthetic is typically 1 minute. Amide anesthetics are metabolized by CYP enzymes and ester anesthetics are metabolized by plasma pseudocholinesterase

Question 30

MOA of lidocaine and procaine

Answer 30

both are sodium channel blockers that inhibit formation of action potentials and thus block nerve impulse conduction by nociceptors

Question 31

MOA of propofol

Answer 31

enhancing the release of GABA; inhibiting sodium channels, or activating the endocannabinoid system through the CNS

Question 32

What is propofol?

Answer 32

General IV anesthetic w/ rapid onset of action, ultra-short duration of action. Used for induction and maintenance of general anesthesia; may induce resp. depression

Question 33

MOA of isoflurane and etomidate

Answer 33

activating GABA receptors (inhibitory neurotransmitter)

Question 34

What is isoflurane?

Answer 34

a general, inhalation anesthetic w/ global CNS depressant effects. LOC, analgesic, amnesia, suppression of peripheral sensations, and depression of resp. Control centers

Question 35

what is etomidate?

Answer 35

a short acting IV anesthetic medication used for the induction of general anesthesia and sedation for short procedures such as reduction of dislocated joints, tracheal intubation, and cardioversion.

Question 36

MOA of ketamine

Answer 36

N-methyl-d-aspartate (NMDA) antagonist (subtype of an excitatory receptor for glutamate)

Question 37

Ketamine usages?

Answer 37

short-acting IV medication that is used mainly for starting and maintaining anesthesia. Uses include sedation in ICU, analgesia, and treatment of bronchospasms.

Question 38

prophylactic treatment for migraines include...

Answer 38

Propranolol (non selective beta antagonist) amitriptyline (tricyclic antidepressant that elevates serotonin levels) Divalproex (anti-seizure medication)

Question 39

treatment of ongoing migraine

Answer 39

NSAIDs Ergotamine: alpha 1 adrenergic agonist—cause vasoconstriction Sumatriptan: selective serotonin receptor agonist Telcagepant: oral CGRP receptor antagonist

Question 40

MOA of nabilone

Answer 40

CB1 and CB2 receptor agonist that has been used in the treatment of chemotherapy-induced nausa/vomiting; treatment of chronic pain (fibromyalgia), and anorexia associated with HIV infections

Question 41

What is the most common endocannabinoid that we produce?

Answer 41

Anandamide

Question 42

MOA of Anandamide

Answer 42

the primary psychoactive component of cannabis, delta 9 THC, produces its effects through weak partial activation of the endocannabinoid system that contains cannabinoid 1&2 receptors