Pain

Question 1

What is the difference between acute and chronic pain?

Answer 1

Acute
<3 months
Change in VS, brief duration, subsides w healing, treat w prn
Sudden onset, subsides quickly, sharp localized sensations w identifiable cause
Response to injury
i.e surgery, injury
Can become chronic when become unremitting, constant, or undertreated

Chronic
>3months
VS WNL, continuous duration, treat w ATC meds
Pain w/o biological value that has persisted beyond normal time & despite usual customary efforts to dx & tx the orig condition & injury

Question 2

What are types of pain?

Answer 2

Nociceptive
Nerve receptor stimulation following a mechanical, thermal, or chemical insult
Purposeful, pain tells you to stop doing whatever is causing pain
Classification:
Visceral
Pain affects visceral organs
Referred, colicky
Squeezing, cramping, bloating
Somatic
associated with muscle, skin, or bone injury, well localized
Stabbing, aching, sharp

Neuropathic 
Abnormal signal processes in CNS
Injury or inflammation of nerves
Peripheral or central in origin
Radicular, stocking like, burning, numb, electric, tingling

Question 3

WHO Pain ladder- what to prescribe?

Answer 3

Added 4th STEP, also add examples
1st step: Tylenol, non-pharm, Ibup, NSAID+ Lyrica, Gabapentin
2nd step: mild to mod (Norco, Oxy+Tylenol)
3: mod to severe (Oxycontin, ATC opioids)

Question 4

Understand the difference between addiction, tolerance and dependence

Answer 4

Addiction
Primary, chronic, neurobiological disease w genetic, psychosocial, & environmental factors influencing its development & manifestations
Impaired control over drug use
Compulsive use
Continued use despite harm
cravings
Tolerance
Chronic use of opioids cause need for upward dose titration to maintain analgesia
Dependence
Emergence of withdrawal sx when drug is abruptly d/c or when dose is rapids decreased

Question 5

CDC Guidance to Prescribing Opioid

Answer 5

When starting prescribe immediate release vs extended release & lowest dose
Caution when increasing dosage >50 MME/day
Avoid increasing >90 MME/day
Acute pain use immediate release and lowest dose for <3d
evaluate therapy in 1-4wks starting chronic pain therapy
Then re-evaluate q3mo
Taper 10% of orig dose/week
Avoid use in pregnancy
If chronic use then seek assistance
Better outcomes when receiving buprenorphine or methadone for opioid use disorder
Avoid benzo & opiates

Question 6

Name opioid drugs. What is the MOA?

Answer 6

Codeine
Morphine
Hydrocodone
Oxycodone
Hydromorphone
Oxymorphone
Fentanyl (not for opioid naive)
Meperidine 

Bind to opioid receptors in the CNS (mu, kappa, or delta) cause inhibition of ascending pain pathways, altering perception of & response to pain, produce generalized CNS depression

“Prevent transmission to brain”

Mu act as analgesic

Question 7

When would you give Oxycodone over Morphine?

Answer 7

Oxycodone is good for renal failure

vs Morphine which isn’t

Question 8

What are side effects of opioids?

Answer 8

Respiratory depression (esp initiation & increase)
sedation confusion n/v     pruritis 
Miosis
Constipation (all the time)
urinary retention
Pruritis
hypotension

Morphine, Dilaudid, & Codeine have active metabolites can accumulate in renal impairment

Question 9

What is naloxone?

Answer 9

Pure opioid antagonist, Competitively binds to opioid receptors w/o producing analgesic response

used for drug OD

Question 10

What are side effects of naloxone?

Answer 10

Flushing
HTN
agitation

Rare: tachycardia, VFib, cardiac arrest

Question 11

Name tricyclic antidepressants? What is their MOA?

Answer 11

Analgesic effects by blocking reuptake of norepinephrine & serotonin

Tricyclic antidepressants (TCA)
Central inhibition of norepi & serotonins reuptake, also block peripheral Na channels

amitriptyline/Elavil
nortriptyline

Question 12

When would you use TCA’s?

Answer 12

Analgesic effects

Neuropathic pain

TCA also chronic pain

Question 13

What are TCA’s side effects?

Answer 13

TCA:
Dry mouth 
wt gain dizziness 
urinary retention confusion sedation
Prolong QT
(give HS)

Question 14

Who must use TCA’s cautiosly?

Answer 14

CAUTION:
Elderly confusion & sedation r/t ANTICHOLINERGIC activity & lead to falls
Amitriptyline on BEERS list

Question 15

Name SNRI meds. What’s their MOA?

Answer 15

Selective norepinephrine reuptake inhibitors (SNRIs)
Potent inhibitor of neuronal serotonin & norepi reuptake & Weak inhibitor of dopamine reuptake

duloxetine/Cymbalta
venlafexine/Effexor

Question 16

What kind of pain are SNRI’s good for?

Answer 16

Analgesic effects

Neuropathic pain
Mulculoskeletal pain

Question 17

What are side effects of SNRI’s

Answer 17

SNRIs:
Nausea, HA, drowsiness
GI disturbances sedation insomnia sweating
Xerostomia confusion

Question 18

What would you monitor for in SNR’s?

Answer 18

kidneys

Question 19

What would you monitor for in TCA’s?

Answer 19

TCA: 
check EKG (QT prolong meds)
Mental status
SI 
HR, BP

Question 20

What drug class would you use to treat neuropathic pain?

Answer 20

anticonvulsants, gabapentin is 1st line

Question 21

What is the MOA of gabapentin?

Answer 21

High affinity-binding sites located throughout brain, correspond to presence of voltage-gated Ca channels which modulate release of excitatory neurotransmitters which participate in nociception

Question 22

What is the MOA of pregabalin/Lyrica?

Answer 22

Exerts antinociceptive & anticonvulsant activity, affect descending noradrenergic & serotonergic pain transmission pathways from brainstem to spinal cord

Question 23

What are the SE of anticonvulsants?

Answer 23

Nausea 
sedation dizziness 
drowsiness
wt gain
Ataxia

Pregabalin: peripheral edema

Question 24

What are monitoring parameters for anticonvulsants?

Answer 24

SI
Sedation
Renal function

Question 25

What are some precautions of gabapentin?

Answer 25

Gabapentin:
Taper up/down
Give HS 
Alter dose base on Cr function, can become: 
Confused
Seizure