Local anesthetics and muscle relaxants Flashcards

1
Q

Local anesthetics that are esters

A

procaine
tetracaine
benzocaine
breakdown easy due to esterases

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2
Q

Local anesthetics that are amides

A
Lidocaine
Mepivacaine
Bupivacaine
Atricaine
Ropivacaine
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3
Q

explain things to consider with inflamed tissue

A
  1. Local anesthetics are weak bases .
  2. low pH in inflammed tissue
  3. Low pH will ionize weak base-more water soluble
  4. in order to increase penetration, must increase pH to let it be in its more nonionized form .
  5. in the cell, the nonionized form is then ionized in order to block sodium
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4
Q

Overdose on Locals will affect which tissues

A

those with voltage gated sodium channels

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5
Q

Stages of overdose with local

A
  1. numbness, metalic flavor, dysgeusea
  2. Tremor, tinnitus, nystagmus, clouding of conscious
  3. Convulsions
    - * at this stage of convulsions: also; indirect cardiac depression including:HTN, tachy, arrythmia.
  4. CNS depression
    - * also cardiac arrest, hypotension, ischemia, AV-dissociation, ECG -widening, low output.
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6
Q

Ach binds only to

A

alpha subunits

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7
Q

Delta and gamma subunits are in

A

NM junction–binding of ACh is still Ach binding to alpha

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8
Q

characteristic feature of muscle relaxants

A

Quaternary amine

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9
Q

Succinylocholine

A

Highly resembles Ach, results in the relaxation of skeletal muscles.

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10
Q

tubocurarine

A

polar and cannot penetrate the BBB.

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11
Q

Atracurium

A

derivative of tubocurarine -used in the clinic

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12
Q

Muscle relaxants with a steroidal skeleton

A

Pancuronium (clinic)
Rocuronium (history of used to kill people)
Vecuronium

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13
Q

Succinylocholine is a depolarizing blocker which means

A

1st step actually causes contraction, but later it prevents sodium channels from closing.

this drug opens sodium channels then leaves sodium channels and they are not allowing it to depolarized

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14
Q

All other drugs and molecules are termed as

A

nondepolarizing blockers-these dont allow depol

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15
Q

Trio of going under anesthesia

A

inducer (benzo, barb)
anelgesic
muscle relaxor

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16
Q

general anesthesia mechanism is not fully understood, but thought to

A

increase GABA and decrease glutamate

17
Q

Certain gen anethetics have been shown to

A

block NMDA

18
Q

Two groups of general anesthetics

A

inhaled , IV

19
Q

Inhaled anesthetics

A
Nitrous oxide
Xenon
Halothane*
Enflurane*
Isoflurane*
Sevoflurane*
Desflurane *
*= volatile liquid anesthetics
20
Q

Pharmokinetics of inhaled anesthetics

A

gets into lungs which are high perfused and gets dissolved into the blood

then to brain and gets redistributed very quickly

21
Q

Minimum alveolar concentration

A

concentration of a vapor in the lungs that is needed to prevent motor response in 50% of subjects in response to pain. Lower = more potent.

22
Q

Pharmacodynamics and toxic effects of inhaled anesthetics

A
  1. decreased cerebreal metabolic rate
  2. 4 stages of increasing depth of CNS depression
    • analgesia
      - excitement (unsure of situation)
      - surgical anesthesia (unconscious)
      • Medullary depression (breathing and cardio)
  3. Nephrotoxicity
  4. Hematotoxicity -careful with nitrous oxide
  5. Malignant hyperthermia- mutation specific - leads to uncontrolled release of calcium from ER which causes an increase in temp which leads to death
  6. Hepatotoxicity-be careful with halothane
23
Q

Propofol/Fospropofol

A

hypnotic but no analgesia
water insoluble , formulated as an emulsion
**potentiation of GABAergic transmission
Rapidly metabolized in the liver
leads to drop in bld pressure and is potent respiratory depressant
antiemetic effect

Fospropofol is water soluble

24
Q

Thipental and methohexital

A

GABAergic neurotransmission –penetrates BBB then redistribution

25
Q

IV benzos

A

Diazepam, Lorazepam, Midazolam – these induce anesthesia

26
Q

Etomidate

A

hypnotic but no analgesia
endocrine side effects
potentiation of gabaergic transmission

27
Q

Ketamine

A

Inhibition of NMDA receptors
Low protein binding compared to other intravenous anesthetics

unpleasant emergence reactions