Pharmacology of Pain N28 Flashcards Preview

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Flashcards in Pharmacology of Pain N28 Deck (21)
1

Pain can be described as

physiological sensation, emotional and physiological reaction to painful stimuli

2

Pathway of pain

nociceptors --> substantia gelatinosa (modulated by enkephalins of descending tracts) --> STT --> thalamus--> cerebral cortex, limbic system, sensory cortex

3

Perception of pain involves

reticular activating system (RAS), limbic system, sensory cortex

4

Autocoids

bradykinin, histamine, prostaglandins, leukotrienes released in response to irritation or tissue injury

5

Autocoids action

stimulate nociceptors or increase their sensitivity

6

Substance P

present in Type C fibers, key role in pain transmission

7

Endorphin/Enkephalin

opioids, modulate processing of pain in the spinal cord, inhibit transmission of pain and Substance P

8

Serotonin

Modulates processing of pain in the spinal cord and thalamus

9

3 mechanisms of altering pain

reduce irritation and inflammation ( NSAIDS, aspirin), block conduction of impulses (anesthetics), modify the pain processing (opioids)

10

NSAIDS, Aspirin, ibuprofen, ect action

Inhibit COX and the formation of prostaglandin which reduced inflammation; decrease sensitivity of nociceptors

11

Local Anesthetics (Lidocaine, procaine)

block Na channels to prevent depolarization and conduction of pain signals; Type C are particularly effected, cause profound analgesia, useful in nerve blocks

12

Opioids (morphine, herion, codeine, meperidine, hydromorphone)

Pain is still present, but it alters the psychic component or reaction to pain in the limbic system, ability to modulate processing of pain in CNS

13

Endorphines, Dynorphins, and Enkephalins

endogenous opioids, act on limbic system and spinal cord, modulate pain pathways and the emotional response to pain

14

4 types of opioid receptors

mu, kappa, delta, and sigma

15

Mu receptors

Brainstem and limbic areas, mediate supraspinal analgesia, respiratory depression, euphoria, dependence

16

Kappa receptors

brainstem and spinal cord, mediate spinal analgesia, meiosis, sedation, and dysphoria

17

Delta receptors

brainstem and limbic system, mediate dysphoria and hallucinations

18

Mophine acts as endophine/enkephalin _____

AGONISTS

19

Naloxone (Narcan) acts as endorphin/enkephalin _______

ANTAGONISTS

20

Role of endogenous opioids in STIMULUS-INDUCED analgesia

Opioid peptides increase due to stimulus, use of opioid antagonist suggest that the pain has been blocked by OPIOIDS only (returns with antagonists)

21

Stimulus-induced analgesia may include

acupuncture, exercise, stress, drugs, electrical stimulation