Local anesthetics and muscle relaxants

Question 1

Local anesthetics that are esters

Answer 1

procaine
tetracaine
benzocaine
breakdown easy due to esterases

Question 2

Local anesthetics that are amides

Answer 2

Lidocaine
Mepivacaine
Bupivacaine
Atricaine
Ropivacaine

Question 3

explain things to consider with inflamed tissue

Answer 3

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

Question 4

Overdose on Locals will affect which tissues

Answer 4

those with voltage gated sodium channels

Question 5

Stages of overdose with local

Answer 5

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.

Question 6

Ach binds only to

Answer 6

alpha subunits

Question 7

Delta and gamma subunits are in

Answer 7

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

Question 8

characteristic feature of muscle relaxants

Answer 8

Quaternary amine

Question 9

Succinylocholine

Answer 9

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

Question 10

tubocurarine

Answer 10

polar and cannot penetrate the BBB.

Question 11

Atracurium

Answer 11

derivative of tubocurarine -used in the clinic

Question 12

Muscle relaxants with a steroidal skeleton

Answer 12

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

Question 13

Succinylocholine is a depolarizing blocker which means

Answer 13

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

Question 14

All other drugs and molecules are termed as

Answer 14

nondepolarizing blockers-these dont allow depol

Question 15

Trio of going under anesthesia

Answer 15

inducer (benzo, barb)
anelgesic
muscle relaxor

Question 16

general anesthesia mechanism is not fully understood, but thought to

Answer 16

increase GABA and decrease glutamate

Question 17

Certain gen anethetics have been shown to

Answer 17

block NMDA

Question 18

Two groups of general anesthetics

Answer 18

inhaled , IV

Question 19

Inhaled anesthetics

Answer 19

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

Question 20

Pharmokinetics of inhaled anesthetics

Answer 20

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

then to brain and gets redistributed very quickly

Question 21

Minimum alveolar concentration

Answer 21

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.

Question 22

Pharmacodynamics and toxic effects of inhaled anesthetics

Answer 22

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

Question 23

Propofol/Fospropofol

Answer 23

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

Question 24

Thipental and methohexital

Answer 24

GABAergic neurotransmission –penetrates BBB then redistribution

Question 25

IV benzos

Answer 25

Diazepam, Lorazepam, Midazolam – these induce anesthesia

Question 26

Etomidate

Answer 26

hypnotic but no analgesia
endocrine side effects
potentiation of gabaergic transmission

Question 27

Ketamine

Answer 27

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

unpleasant emergence reactions