MAGA (Brooke's Deck, Exam II) Flashcards
What enzyme catalyzes the synthesis of prostaglandins?
COX (Cyclooxygenase)
This form of COX is responsible for gastric protection, hemostasis, and renal function…
COX-1
COX-1 or COX-2?
Ubiquitous, “physiologic”, inhibition of this enzyme is responsible for many adverse effects.
COX-1
COX-1 or COX-2?
Pathophysiologic, expressed at sites of injury, not protective.
COX-2
COX-2 propagation is responsible for which symptoms?
Pain, inflammation, and fever
What are the three main properties of NSAID drugs?
Analgesic
Anti-inflammatory
Antipyretic
Are the following drugs non-specific or COX-2 selective?
–Ibuprofen, naproxen, aspirin, and ketorolac–
What gastric symptomology would be seen with administration of these drugs?
Non-Specific
Increased gastric irritation with these drugs
Multimodal includes _____ acting anesthetics agents and _______ sparing components.
short acting; Opioid sparing.
Celecoxib (Celebrex), Rofecoxib (Vioxx), Valdecoxib (Extra), Parecoxib (Dynastat) are all examples of what?
COX-2 Selective NSAIDs
Do COX-2 selective NSAIDs affect platelets?
No
Because COX-2 selective NSAIDs have no effect on platelets, this would increase the chance of what pathology?
Clotting (think MI and CVA)
COX-2 selective and nonspecific inhibitors have _____________ analgesia
Comparable
What was the first COX-2 inhibitor that decreases PG synthesis?
Celecoxib (Celebrex)
What is the dosage for Celebrex?
200 to 400 mg PO QD
Celebrex reaches its peak in…
3 hours
List some alternatives to treat pain.
PT & OT, Chiropractic care, acupuncture, massage, yoga, weight loss, cold/heat, OTC medications, TENS unit…etc.
What are the 2 classes of opioids?
1) Phenanthrenes (L-isomers have opioid activity; morphine, codeine)
2) Benzylisoquinolones (Lack opioid activity; Papaverine, noscapine)
What drug class does Ondansetron fall into?
What was it first developed for?
What CYP450 is relevant to ondansetron?
It is the first 5-HT3 antagonist
-It was approved for CINV
-Responsiveness decreased by variations in the CYP2D6 activity
Ondansetron is equivocal to what two drugs in its treatment of N/V?
Droperidol & Metoclopramide
What are the side effects of Ondansetron?
HA, diarrhea, and some QT prolongation!
What is the duration & dose of Ondansetron? (pediatric?)
Duration/plasma half life: 4 hours
Dose: Adults: 4 - 8 mg IV
Dose: Pediatrics: 0.1 mg/kg IV
What is the MOA of Corticosteroids in the treatment of N/V?
Why are Corticosteroids used with 5-HT3 (Ondansetron) & droperidol?
- MOA is unknown: It works on glucocorticoid receptors in Nucleus Tractus Solitarius (NTS).
- Corticosteroids potentiate 5 HT3 antagonists and droperidol
What is the dose for Dexamethasone (Decadron)?
What is the MOA of Dexamethasone (Decadron)?
4 - 8 mg IV
MOA: Anti-inflammatory; inhibition of phospholipase and cytokines and stabilization of cellular membrane.
What is the delay of onset of Dexamethasone (Decadron)? How long does efficacy persist?
Are there any adverse effects of a single dose of Dexamethasone (Decadron)?
What occurs if it is pushed fast?
- Onset: 2 hours. Efficacy: 24 hours.
- Nope
- Perineal burning/itching
According to the TXWES medication guide, what are the doses for Acetaminophen (Ofirmev), Ketorlac (Toradol), & Ibuprofen (Caldor).
Slide 62
A 50 y/o, 60 kg female patient received a Lidocaine initial dose of 1 mg/kg with a subsequent infusion of 1.5 mg/kg/hour for 1.5 hours. How much total Lidocaine in mgs did she receive in the PACU?
60kg x 1 mg/kg = 60 mg
60 kg x 1.5 mg/kg = 90 mg (1 hour)
(60 kg x 1.5mg/kg = 90 mg)/2 = 45 mg (30 minutes)
60+90+45 = 195 mg total!!!
Multidose lidocaine vials are used for _____.
infiltration or peripheral nerve block.
Lidocaine is an ______ structure local anesthetic.
- Amide (amides anesthetics have 2 “i”s)
How is lidocaine metabolized?
Liver
What is the IV bolus and infusion dose of lidocaine?
When should the infusion be terminated?
- 1 to 2 mg/kg IV bolus over 2-4 min.
- 1 to 2 mg/kg/hr infusion
- Terminated within 12-72 hours.
Regarding Gabapentin’s preemptive analgesia, What 3 studies/ procedures is it used in?
- Spine surgeries
- Orthopedic procedures
- Major abdominal procedures.
(slide 27)
What is the PO dose of preemptive Gabapentin?
When should we give it?
What is it’s MOA?
300-1200mg PO
1-2 hrs prior to OR
GABA analogue
For Preemptive Gabapentin, what patient population is it contraindicated for?
- MG and Myoclonus patients
- Reduce dose in elderly patients
What are Gabapentin’s side effects?
Think ↑GABA effects
- Somnolence
- fatigue
- ataxia
- vertigo
- constipation
- seizures
- wt gain
For Ofirmev, what is the Dose, Peak effect time (PO/IV), and duration?
What is the MOA for Ofirmev?
Reduces prostaglandin metabolites
For Ketorolac, what is the:
- MOA
- Peak
- Dosing
MOA: Inhibits PG synthesis by inhibiting COX 1 and COX 2
Peak: 45 to 60 minutes IV
Dose: 15 to 30mg q6h (1/2 dose in elderly)
Max Dose: 60-120mg QD
What are some contraindications to consider when giving Toradol?
- Severe Renal impairment
- Risk for bleeding
- CAD
- CABG
- Pregnant
- NSAID allergy
Lidocaine plasma concentration of ____ causes what?
1-5 mcg/ml = ?
5-10 mcg/ml = ?
1-5 = analgesia
5-10 = circum-oral numbness; tinnitus; skeletal muscle twitching; systemic HYPOtension; myocardial depression
Lidocaine plasma concentration of ____ causes what?
10-15 mcg/ml = ?
15-25 mcg/ml = ?
These are OD levels
10-15 = Sz’s; unconsciousness
15-25 = apnea (pons & medullary depression); coma
Which procedure would you expect to see a high use of Lidocaine?
(HINT: Castillo mentioned this)
EGD’s
Castillo gives a “boatload” of lidocaine in EGD’s
(per Castillo)
If we give Lido w/ Epi, should the dose be higher or lower?
Why?
Higher: epinephrine will locally vasoconstrict and prevent lidocaine leakage into the intravascular space.
How is lidocaine overdose treated?
Lipid rescue
Which patients receive magnesium sulfate most often per Castillo?
Preeclamptic & eclamptic OB patients.
This med has anti-nociceptive effects by antagonizing the NMDA receptor and “probably” potentiates opioids centrally and peripherally.
Magnesium
Mg++ regulates which four cellular functions?
- Ca++ access intracellularly.
- Neurotransmission
- Cell signaling
- Enzyme function
Which ion has limited movement across the BBB?
Mg⁺⁺
What conditions are contraindicative for magnesium administration?
Myasthenia Gravis & Renal Failure
What adverse side effects could occur with Mg++?
Hypotension, bradycardia, ataxia, somnolence, decreased muscular tone.
What is Mg⁺⁺ dosing for the following two situations?
Preop:
Intraop:
- Preop: 50 mg/kg IV
- Intraop: 8 mg/kg/hr IV
What opioid requirement does the use of Mg++ significantly decrease?
Fentanyl
Ibuprofen:
- MOA
- Dose
- Peak
- Excretion
- Contraindications
- COX 1 & 2 Inhibition = ↓ PG synthesis
- 200 - 800 mg q6h (max:3200mg QD)
- 1-2 hours
- Urine & Bile
-C/I: Nephropathy, CABG, bleeding disorders, wound healing
Using multimodal anesthesia, what 2 meds might we give in preop to better control pain later?
Acetaminophen 1000 mg PO, Gabapentin 300 mg PO
With non-opioid anesthesia, what medications are used for induction?
Propofol, Lidocaine, Ketamine, volatile anesthetics. Paralytic if needed.
What is the MOA of gabapentin?
GABA Analog actions:
- Blockage of VG Ca⁺⁺ channels
- inhibits release excitatory neurotransmitters
- Descending inhibitory tract enhancement
Is gabapentin lipid soluble?
What percentage protein-binding occurs with gabapentin?
What’s it’s E 1/2 time?
- Yes; Lipid soluble
- 0% (not protein-bound)
- Brief E 1/2 time (5-7hr)
Does gabapentin have any drug-drug interactions?
No drug-drug interactions
What are indicated uses for gabapentin? (3)
- Seizures
- Neuropathic pain
- Chronic pain syndromes.
