21 Fall Pharm Final Oral Flashcards
Desflurane VP
669mmHg
Desflurane MAC
6%
Desflurane B:G
0.42
Desflurane O:G
19
volatile agents MOA
Unknown – likely involves NMDA receptors, tandem pore K+ channels, VG-Na+ channels, glycine receptors, and GABA receptors in the cerebral cortex, brain stem arousal centers, central thalamus, and spinal cord.
Isoflurane MAC
1.2%
Isoflurane VP
238mmHg
Isoflurane B:G
1.4
Isoflurane O:G
91
Sevoflurane MAC
2%
Sevoflurane B:G
0.68
sevolurane O:G
50
sevoflurane VP
157mmHg
Nitrous Oxide MAC
104%
Nitrous Oxide O:G
1.4
Nitrous Oxide B:G
0.47
Nitrous Oxide VP
38770
What is the MOA of magnesium?
Mag works in opposite direction of calcium, calcium excites, mag inhibits
The 3As in anesthesia and which location in the brain.
amnesia (brainstem), analgesia (thalamus), and areflexia (spinal cord) (no SNS/PSNS changes in V/S)
How to treat MH?
Na+ dantrolene 1.5 mg/kg or Ryanodex
Stages of anesthesia
Stage I – Amnesia & Anesthesia
Stage II – Delirium & Excitation
Stage III – Surgical Anesthesia
Stage IV – Anesthetic overdose
In what population should you avoid using desflurane?
Stinky bad boy!!! Avoid in patients with reactive airway disease
Which inhalational agent is best for inhalational induction
Sevoflurane
What complication can sevoflurane produce? How to mitigate? Surgery implication?
If used with Lyme, can create nephrotoxic compound A. Use lime can reduce risk. Give flow >2lpm
What is this?
desflurane
What is this
isoflurane
what is this?
Sevoflurane
Wha is special about Isoflurane?
Most potent, slowest. concern for coronary steal in HoTN
What are contraindications of nitrous oxide?
- methionine synthase pathway deficiency
- surgery involving gas filled spaces
- middle ear
- pneumothorax
- intraocular air bubble
- 1st tremester
- increased ICP
- long cases > 6hr
The ideal anesthetic agent
- Non-irritating to the respiratory tract
- Rapid induction and emergence
- Chemically stable (non-flammable)
- Produce amnesia, analgesia and areflexia
- Potent
- Not metabolized and excreted by respiratory tract
- Free of toxicity and allergic reactions
- Minimal systemic changes
- Uses a standardized vaporizer
- Affordable
Is propofol an acid or a base?
Acid
Propofol induction dose?
1.5mg/kg-2.5mg/kg
Propofol MAC (endoscopy) dose
25-100 mcg/kg/min
Propofol TIVA dose?
100mcg-300mcg/kg/min
Propofol antiemetic dose?
10mg IV
Propofol antipruritic dose?
10mg IV
Propofol anticonvulsive dose?
1mg/kg IV
Propofol MOA
GABA modulator (allosteric) – Cl- influx hyperpolarizes neuron (IPSP).
Propofol t1/2
30min - 1hr
Propofol Vd
2.5-3.5
Propofol active metabolites
4- hydroxypropofol
What’s propofol’s biggest advantage?
Rapid return to consciousness with minimal residual effect
Unique about propofol metabolism
Clearance exceeds hepatic blood flow (liver)
Tissue uptake in the lungs
Propofol context sensitive t1/2
<40 min
Factors that affectd FA/FI
Factors that affect the FA/FI ratio include:
- the delivered inspired anesthetic concentration,
- the blood-gas partition coefficient of the inhalation agent,
- alveolar ventilation (VA),
- cardiac output (Qt),
- and the distribution of Q to the vessel-rich organs (i.e., heart, brain, kidneys, and liver).
Etomidate MOA
GABA modulator
What does GABA stand for?
Gamma-aminobutyric acid
How long does propofol last?
8-10 min
How long does etomidate last?
5-15 min
Contraindication of etomidate
Porphyria, septic shock (etomidate causes suppressed 11-betahyroxylase for 8 hrs, low cortisol)
How is etomidate metabolized?
hydrolysis, plasma esterase and microsomal enzymes in the liver.
Etomidate induction dose
0.2-0.4mg/kg IV
Is Etomidate an acid or base?
It’s a base.
Etomidate t1/2
2-5 hrs
Ketamine induction dose
1-2.5mg/kg
ketamine t1/2
2-3 hrs
Etomidate VD
2.2-4.5
Ketamine Vd
3.5-4.5
Ketamine MOA
NMDA (N-methyl-D-aspartate) non-competetive antagonist ==> dissociative amnesia
Ketamine dart dose, onset time
Ketamine PO dose, onset time
dart 4-8mg/kg, <10 min onset
PO 10 mg, 10-20 min onset
Ketamine active metabolite
metabolized by liver, norketamine
ketamine contraindication
increased ICP
eye procedures
eye trauma
high emergence delirium risk
benzodiazepine MOA
allosteric agonist on GABA
benzodiazepine effects
anxiolytic
muscle relaxant
anticonvulsant
anterograde amnesia
What are side effect of benzodiazepine?
STRONG synergistic effect with opioids (RESPIRATORY DEPRESSION)!!!
midazolam induction dose
0.02-0.04mg/kg
midazolam Vd
High
How is midazolam metabolized? active metabolite?
rapid metabolism in liver d/t imidazole ring.
active metabolite:
- 1-hydroxymidazolam, which has half the activity
- 4- hydroxymidazolam, nondetectable amount
midazolam t1/2
2 hrs
Is midazolam injection painful? why?
water soluble with imidazole ring. only benzo with painless injection
Is midazolam an acid or base?
Base
Is diazepam Vd?
High
diazepam t1/2
>40 hrs
How is diazepam metabolized? Active metabolites?
Liver I (oxidative)
Active metabolites:
- desmethyl diazepam (responsible for long t1/2)
- Oxazepam
- temazepam
diazepam contraindication
don’t give to pt with porphyria
t1/2 is pt’s age, careful with old pt.
what can diazepam be used for?
DT, anticonvulsant, pt with tetany, lumbar disc disease.
Lorazepam t1/2
14 hrs
What is special about lorazepam’s PK?
Slowest onset (1-2 min) but most potent
What do you use to reverse benzodiazepine?
flumazenil
dosage of flumazenil
give 0.2mg initially, usually have effect in 2 min.
then give 0.1mg every 60 seconds. 0.5-1mg should completely reverse. if given 5mg and pt still not responsive, something else is going on.
Barbiturates MOA
GABA agonist,
also works on adenosine, nAchR, glutamate
barbiturates contraindication
Do not give pt with porphyria
What drug should not given to pt with porphyria?
Barbiturates
Diazepam
Etomidate
If barbiturates are infused arterially, what to do?
papaverine, heparinization, arteriodilate with regional anesthesia
Thiopental induction dose?
2.5-5mg/kg
how is Thiopental metabolized? Acftive metabolite?
Liver I phase I
Active metabolite: pentobarbital
Thiopental Vd?
Large
What is methohexital induction dose?
What is methohexital pediatric dose?
1-2mg/kg
25mg/kg
what is methohexital used for?
ECT to lower seizure threshold
Opioid MOA
- Pre synaptic – inhibit release of acetylcholine, dopamine, norepinephrine and Substance P
- Post synaptic – increased K+ conductance = decreased function
opioids major side effects
- CV – bradycardia, impaired SNS response, orthostatic hypotension, SYNERGISM ↓↓ BP with benzos and nitrous oxide!!!
- Resp – ↓↓ responsiveness to CO2, deep, slow breaths. ↑↑ airway resistance.