Test 3

Question 0

transition from acute to chronic pain can be initiated or maintained by peripheral and/or central mechanisms

Answer 0

dorsal root ganglion
cord
supratentorial

Question 1

chronic pain definition

Answer 1

pain that has no biological benefit and lasts longer than 3 months (or the normal healing time)

Question 2

what is the clinical manifestation of peripheral sensitization?

Answer 2

hyperalgesia

Question 3

what is peripheral sensitization?

Answer 3

enhanced excitability of nerves
reduced nociceptive thresholds
renders high-threshold nerve endings responsive to normally non-noxious stimuli

Question 4

some effects of nerve injury

Answer 4

1. sprouting of new hyperexcitable nerve endings
2. neuroma
3. reduced thresholds

Question 5

pain caused by CHANGES in peripheral or CNS is defined as

Answer 5

neuropathic pain (which leads to hyperalgesia and allodynia)

Question 6

central sensitization involves __ neurons, which is responsive to __

Answer 6

second order wide dynamic range
responsive to GLUTAMATE (NMDA receptor)

(usually in the dorsal horn)

Question 7

what’s the difference between acute and chronic pain?

Answer 7

constant dumping of quanta of glutamate and opening of the magnesium plug

Question 8

how do anticonvulsants help?

Answer 8

inhibit neuron excitation and stabilize membrane

Question 9

what are the first generation anticonvulsants?

Answer 9

carbamazepine and phenytoin

Question 10

what are the second gen anticonvulsants?

Answer 10

gabapentin and neurontin

Question 11

what do anticonvulsants treat?

Answer 11

postherpetic neuralgia, diabetic neuropathy, trigeminal neuralgia, others

Question 12

what is the mech of action of anticonvulsants?

Answer 12

block alpha 2 delta subunit of PREsynaptic voltage gated calcium channels in CNS

Question 13

how do antidepressants work?

Answer 13

1. block reuptake of serotonin and norepi, which are inhibitory neurotransmitters in the descending inhibitory pathway
2. block sodium and ca++ channels
3. decrease prostaglandin and TNF
4. block NMDA receptors
5. enhance opioid receptors

Question 14

How long does it take for antidepressants to enhance opioid receptors?

Answer 14

4-10 days

Question 15

what are the three classes of antidepressants?

Answer 15

tricyclics, selective norepi reuptake inhibitors, and selective serotonin reuptake inhibitors

Question 16

name 2 selective norepi reuptake inhibitors

Answer 16

effexor (venlafaxine) and cymbalta (duloxetine)

Cymbals effect norepi

Question 17

name 2 selective serotonin reuptake inhibitors

Answer 17

prozac (fluoxetine) and celexa (citalopram)

Prozac is the flux that holds Alexis’ pram together

Question 18

what are the side effects of tricyclics?

Answer 18

muscarinic (think glyco), histaminergic (think benadryl), and adrenergic (think alpha blocker)

caution: recent MI, prolong QT interval

Question 19

what might happen if you combine a selective norepi reuptake inhibitor with a selective serotonin reuptake inhibitor or a triptan?

Answer 19

serotonin syndrome (anxiety, agitation, delirium, seizures, hyperthermia, diaphoresis, tachycardia, htn or hypotension, hyperreflexia, myoclonus, muscle rigidity)

Question 20

how would you treat serotonin syndrome due to concomitant use of SNRI and SSRI

Answer 20

lipid emulsion

Question 21

how do corticosteroids work?

Answer 21

prevent release of arachidonic acid by inhibiting phospholipase A2 on cell membranes (precursor of prostaglandins)

Question 22

what nerve fibers are blocked by corticosteroids?

Answer 22

C fibers

Question 23

the effects of corticosteroids are dependent on the degree of HPA axis suppression

Answer 23

hypothalamic - pituitary - adrenal axis

Question 24

how long can an epidural steroid injection cause HPA suppression?

Answer 24

4-5 days after injection up to 5 weeks

in the event of major surgery during that time, you should give them a dose of exogenous steroid

Question 25

how does methadone work?

Answer 25

the S isomer antagonizeS NMDA receptorS and inhibits reuptake of Serotonin and norepi

the R isomer binds to opioid Receptors

Question 26

side effects of methadone

Answer 26

resp depression, excessive sedation, QT interval