Non-Opioids

Question 1

Nonsteroidal anti inflammatory drugs (NSAIDs) are ___

Answer 1

cyclooxygenase COX inhibitors

Question 2

cox inhibitors (aka NSAIDs)

Answer 2

prevent binding of arachidonic acid to cox enzyme and inhibit production of prostaglandins

Question 3

where do NSAIDs act on the pain pathway

Answer 3

1st order neuron, do not act centrally

Question 4

cox 1 isoenzyme

Answer 4

constitutively expressed (always on), maintenance of renal function, mucosal protection of GI tract, production of thromboxane A2

Question 5

What does thromboxane A2 do?

Answer 5

released by plts. to attract more plts. (like axe body spray ;-) )

Question 6

cox 2 isoenzyme

Answer 6

induced by inflammatory mediators, mediation of pain, inflammation, fever

Question 7

toradol (ketorolac)

Answer 7

15 mg IV or IM q6h, don’t give with impaired renal function

Question 8

celebrex (celecoxib)

Answer 8

cox 2 inhibitor, used in ortho surgery usually part of multimodal protocols, have less GI toxicity, increased CV risk

Question 9

celebrex (celecoxib) dose

Answer 9

400 mg PO preop

200 mg BID x 5 days postop

Question 10

PK of NSAIDs

Answer 10

WEAK ACIDS
low Vd (.1-.3 L/kg) - good thing
rapid GI absorption
increased protein binding
liver metabolizes most
eliminated primarily by renal and biliary excretion

Question 11

Side effects of NSAIDs

Answer 11

platelet function primarily thru cox 1
GI complications range- mild ulcer to perforation and bleeding (at risk: elderly, helicobacter pylori infection, hx of ulcer, concominant use of ASA, anticoags, or corticosteroids)
CV complications- increased risk of MI, HF, and HTN
Renal - changes to function including sodium excretion, tubular function, interstitial nephritis (at risk: CHF, already renal disease, hx diabetes, HTN, atherosclerosis, hypoalbuminemia)
Liver - liver failure, elevated transaminase levels

Question 12

Risk of anaphylaxis with NSAIDS

Answer 12

allergic rhinitis + nasal polyps + asthma

Question 13

NSAIDs drug interactions

Answer 13

increased bleeding with antiplatelet agents

Question 14

ASA

Answer 14

rapidly metabolized by plasma esterases, erythrocytes and liver
uses: analgesic, irreversible platelet. inhibitor

Question 15

ASA overdose

Answer 15

related to drug acidity and prostaglandin inhibition
symptoms: N/V, abd pain, hearing impairment, CNS depression
can lead to met. acidosis, renal failure
urine alkalinization increases salicylate elimination

Question 16

Acetaminophen (tylenol)

Answer 16

analgesic and antipyretic- does have central effect thru activation of serotonergic pathways and antagonism of NMDA, substance p and nitric oxide pathways
no antiinflammatory actions

Question 17

acetaminophen dosing

Answer 17

325-650 mg q4-6h (don’t exceed 4000mg/24hr or 2000mg in alcoholics)
ofirmev (IV) 1000 mg q6h

Question 18

PK of acetaminophen

Answer 18

metabolized in liver
causes liver failure d/t damage from N-acetyl-p-benzoquinoneimine depleting glutathione
remove by use of charcoal and replace glutathione (acetylcysteine)

Question 19

gabapentin

Answer 19

acts on voltage gated Ca2+ channels inhibiting glutamate
can be used as anticonvulsant
used in multimodal pain regimens
absorbed in duodenum and minimal protein binding and excreted with minimal metabolism

Question 20

gabapentin dose and side effects

Answer 20

preop: 1200 mg 1-2hr before surgery
600 mg q8h x 14 days

side effects: sedation, dizziness, headache, visual disturbances

Question 21

lidocaine

Answer 21

amide, weak base, pKa slightly above pH

MOA not certain (may involve Na+ channels, and block priming of polymorphonuclear granulocytes)

Question 22

Lidocaine PK and dosing

Answer 22

first pass extraction in lungs, metabolized in liver (prolonged under GA)

dose: 1.5 mg/kg bolus, 1-2 mg/kg/hr infusion

not beneficial in all surgeries

Question 23

magnesium sulfate

Answer 23

analgesic properties related to: Regulation of calcium influx into cell, antagonism of NMDA receptors in CNS

dose: 30-50 mg/kg bolus, 10 mg/kg/h infusion

side effects: bradycardia, hypotension

prolongs muscle relaxants, tends to sedate

Question 24

capsaicin

Answer 24

transient receptor potential vanilloid (TRPV1) channel agonist (activation releases high intensity impulses and release of substance p)

applied topically for neuralgia

OTC: .025, .075, .25% creams/patch

Question 25

ketamine

Answer 25

NMDA antagonist modulates central sensitization
base, less lipophilic than propofol, act centrally

dose: .5-1 mg/kg before incision

side effects: psychomimetic, dizziness, blurred vision, N/V

Question 26

dexmedetomindine

Answer 26

selective alpha 2 agonist (blunts central sympathetic response)

dose: .5-2 mcg/kg

side effects: hypotension, bradycardia

Question 27

peripherally acting opioids can reduce

Answer 27

plasma extravasation, vasodilation, proinflammatory neuropeptides, immune mediators and tissue destruction