Pharm: Anesthetics Flashcards
1
Q
inhalation anesthetics
A
make patient unconscious
2
Q
IV anesthetics
A
make patient unconscious
highly lipid soluble: need pH adjustment or surfactant (can lead to toxicity)
INSTANTANEOUS compared to inhaled
rate limiting step of elimination: release from adipose
LONG T1/2, SHORT duration of action due to redistribution
3
Q
nitrous oxide
A
gas inhalation anesthetic potentiate 2 pore K channel inhibit NMDA, nicotinic ACh, serotonin, kainate RAPID onset maintains protective reflexes (resp. and CV) can us less volatile agent PAIN RELIEF teratogen in animals inhibits vit. B12 synthetase 2ND GAS EFFECT, DIFFUSIONAL HYPOXIA, INCREASE PRESSURE AE: N/V (important in anesthesia)
4
Q
volatile liquids
A
-urane inhalation anesthetic potentiate GABA(A) explosive: add FLUORINE (can cause renal damage) NO pain relief LOSS of REFLEXES AE: MALIGNANT HYPERTHERMIA
5
Q
halothane
A
volatile liquid SLOW onset and recovery most POTENT hepatic metabolism AE: ARRHYTHMIA, HEPATIC
6
Q
enflurane
A
volatile liquid
MUSCLE RELAXATION
AE: SMELL, SEIZURE
7
Q
isoflurane
A
volatile liquid
potentiate 2 pore K channel, glycine, serotonin, kainate
inhibit inward rectifying K channel, AMPA
MUSCLE RELAXATION
AE: SMELL
8
Q
desflurane
A
volatile liquid inhibit: NMDA, voltage gated K channel, kainate most RAPID onset and recovery least potent AE: SMELL
9
Q
sevoflurane
A
volatile liquid
potentiate: glycine
inhibit: NMDA, serotonin, AMPA
RAPID onset and recovery
10
Q
thiopental
A
IV anesthetic: induction agent
barbiturate
CYP induction
AE: PORPHYRIA
11
Q
propofol
A
IV anesthetic: induction agent
potentiate GABA(A) and glycine
minor NMDA inhibition: blocks glutamate from binding receptor
high concentration: acts like GABA
ANTIEMETIC
AE: INFUSION SYNDROME, CV/ organ failure when used for long time
12
Q
etomidate
A
IV anesthetic: induction agent potentiate GABA(A) and 2 pore K channel NO CV effects AE: inhibit STEROIDS do NOT use in ICU
13
Q
ketamine
A
IV anesthetic, IM
inhibit NMDA: PHYSICALLY occludes channel
inhibit muscarinic ACh
increase: cerebral blood flow, ICP, CV (HR, MAP, CO)
NO effects on respiratory rate
other: ANALGESIC, intact PHARYNGEAL/ LARYNGEAL REFLEX, BRONCHODILATOR
AE: emergence HALLUCINATION, EYES OPEN when unconscious (dissociative)
14
Q
diazepam
A
IV anesthetic
benzodiazepine
perioperative drug: sedation
LONG duration
15
Q
lorazepam
A
IV anesthetic
benzodiazepine
perioperative drug: sedation
16
Q
midazolam
A
IV anesthetic
benzodiazepine
SHORT duration
17
Q
morphine
A
IV anesthetic opioid LONG LASTING SLOW onset peri-operative analgesia
18
Q
meperidine
A
IV anesthetic
opioid
19
Q
fentanyl
A
IV anesthetic peri-operative analgesia and RSI neruolept-analgesia agent opioid FAST ONSET SHORT acting decrease sympathetic response during intubation
20
Q
remifentanil
A
IV anesthetic
opioid
ULTRA SHORT ACTING
no accumulation: RAPID LOSS OF ANALGESIA
21
Q
benzodiazepine
A
potentiate GABA(A): allosteric change (shift dose response and increase POTENCY)
CEILING EFFECT: safe
ANTICONVULSANT, AMNESIA, ANXIOLYTIC
minimal CV and respiratory depression
longer onset compared to other IV anesthetics
NO ANALGESIA
22
Q
barbiturates
A
potentiate GABA(A): PROLONG binding (increase EFFICACY)
high concentrations: open GABA channel in absence of GABA: COMA, DEATH
inhibit muscarinic ACh, AMPA, kainate
CYP inducer
23
Q
opioid: reasons for/against use
A
For
- no effect on heart
- decrease airway reflex: intubation
- pain relief
- no malignant hyperthermia
- maintain regional blood flow
Against
- incomplete amnesia
- histamine reaction
- increase blood req.
- respiratory depression
- CV instability
24
Q
opioid
A
OP1-3 receptors in spinal cord and CNS
AE: bradycardia, hypotension,, HTN, RESPIRATORY DEPRESSION, loss of response to PaCO2, WOODEN CHEST, increase CBF and ICP; CONSTIPATION, MIOSIS, N/V
25
amide type local anesthetic
prefix contains i
injection or infiltration
metabolized in liver
26
ester type local anesthetic
NO i in prefix
injection or infiltration
metabolized in any tissue by esterases: SHORTER DURATION
genomic changes in enzyme effect accumulation
27
topical only anesthetics
poor aqueous solubility and/or undesirable toxicity
28
EMLA (eutectic mixture of local anesthetics) cream
lidocaine and prilocaine
| apple to skin with occlusive dressing before painful procedure
29
LET (lidocaine-epinephrine-tetracaine)
use in pediatric ED
liquid application to lacerations req. stitches
analgesia and vasoconstriction
30
vasoconstrictors: use with local anesthetics
1. improve intensity of local anesthetic
| 2. increase duration of blockade
31
local anesthetics
-caine
bind INNER surface of voltage gated Na channel and inhibit AP in active or inactive state (does not bind in resting state)
act on nerve AXON
unconsciousness ONLY with incorrect administration
lipophilicity: benzene ring
AE: allergy (give other type of local anesthetic); allergy to preservative (sulphites)
32
lidocaine
amide type local anesthetic
peri-operative RSI
RAPID ONSET
decrease ICP and bronchospasm in intubation
33
mepivacaine
amide type local anesthetic
LEAST POTENT
SLOW ONSET
34
prilocaine
amide type local anesthetic
RAPID ONSET
AE: METHEMOGLOBINEMIA
35
bupivacaine
```
amide type local anesthetic
POTENT
LONG ACTING
SLOW ONSET
AE: CARDIOTOXIC if systemized
```
36
ropivacaine
```
amide type local anesthetic
POTENT
LONG ACTING
SLOW ONSET
reduced cardiotoxicity (reason produced)
```
37
articaine
```
amide type local anesthetic
ester link cleavage: inactivation
lipophilicity: thiophene ring
RAPID ONSET
BONE PENETRATION: dental block
AE: PARESTHESIA
```
38
procaine
ester type local anesthetic
LEAST POTENT
SHORT ACTING, SLOW ONSET
39
chloroprocaine
ester type local anesthetic
| SHORT ACTING, FAST ONSET
40
tetracaine
ester type local anesthetic
POTENT
LONG ACTING
SLOW ONSET
41
cocaine
ester type local anesthetic
42
benzocaine
topical only local anesthetic: mucous membranes and skin
| AE: METHEMOGLOBINEMIA
43
dyclonine
topical only local anesthetic: mucous membranes and skin
44
dibucaine
topical only local anesthetic: SKIN ONLY
45
pramoxine
topical only local anesthetic: SKIN ONLY
46
epinephrine
vasoconstrictor
peri-operative anaphylaxis
DI: B blocker, TCA, halothane, HTN, heart block, cerebral vascular insufficiency
CI: close angle glaucoma, HF, CAD, HTN, arrhythmia, cerebrovascular disorder, DM, hyperthyroid
47
phenylephrine
vasoconstrictor
| peri-operative CV support for hypotension
48
oxymetazoline
vasoconstrictor
49
phentolamine
alpha adrenergic blocker
reversal agent for local anesthetics
increases blood flow to anesthetized area
50
perioperative drugs: sedation and reduced anxiety
benzodiazepine
phenothiazines
antihistamine
51
preoperative drugs: analgesia
opioids
| NSAID
52
preoperative drugs: antimicrobial
aimed at most likely agents
| cefazolin, cefotetan, cefoxitin, vancomycin
53
preoperative drugs: RSI
intubation
1. lidocaine: decrease ICP and bronchospasm
2. fentanyl: decrease sympathetic response
3. atropine: mitigate bradycardia response of SCh
4. vecuronium: mitigates ICP response of SCh
5. succinylcholine: NMB
6. sedative
54
preoperative drugs: anaphylaxis
stop drug, give O2 and epinephrine, volume expansion
prophylaxis: cimetidine, diphenhydramine
other: aminophylline, steroids, Na bicarbonate
55
preoperative drugs: aspiration pneumonitis
```
H2 blocker
antacids
Bicitra, Polycitra
metoclopramide
water: facilitates emptying
```
56
preoperative drugs: N/V
antihistamines
phenothiazines
also drugs that act on: DA, muscarinic and opiate receptors
57
preoperative drugs: anticholinergic
reduce secretions, mitigate reflex bradycardia
antihistamines
phenothiazines
atropine, scopolamine, glycopyrrolate
58
preoperative drugs: CV support
for hypotension: DA, phenylephrine, ephedrine
| HTN: nitroprusside, trimethaphan
59
promethazine
```
preoperative sedation
phenothiazine
sedative, antiemetic
inhibit: DA, ACh, Histamine
AE: lowers threshold for seizures
```
60
hydroxyzine
preoperative sedation
phenothiazine
sedative, anti-emetic
inhibit: DA, ACh, Histamine
61
diphenhydramine
preoperative sedation
antihistamine, anticholinergic, anti-emetic
bronchodilator, analgesic
Tx: allergic rxn to local anesthetics
62
codeine
peri-operative analgesia
| opioid
63
ketorolac
peri-operative analgesia
NSAID: PG inhibition (COX inhibition)
AE: bleeding, reduced fracture healing
64
ibuprofen
peri-operative analgesia
NSAID: PG inhibition (COX inhibition)
AE: bleeding, reduced fracture healing
65
cefazolin
peri-operative antimicrobial
| effective against: staph, strep
66
cefotetan
peri-operative antimicrobial
| effective agains: bowel anaerobes
67
cefoxitin
peri-operative antimicrobial
| effective agains: bowel anaerobes
68
vancomycin
peri-operative antimicrobial
use: MRSA
do NOT use routinely
69
veuronium
peri-operative RSI
| mitigates ICP response of SCh during intubation
70
atropine
peri-operative RSI and anticholinergic
most potent vagolytic
mitigate bradycardia response of SCh in intubation
71
aminophylline
peri-operative anaphylaxis
72
hydrocortisone
peri-operative anaphylaxis
73
methylprednisolone
peri-operative anaphylaxis
74
cimetidine
peri-operative aspiration pneumonitis
| H2 blocker
75
ranitidine
peri-operative aspiration pneumonitis
| H2 blocker
76
bicitra
peri-operative aspiration pneumonitis
| antacid
77
polycitra
peri-operative aspiration pneumonitis
| antacid
78
metoclopramide
peri-operative aspiration pneumonitis and N/V
gastrokinetic agent: accelerates gastric emptying
AE: sedation, lower seizure threshold, potentiation of EXTRA-PYRAMIDAL effects
antagonized by: anticholinergics, narcotics (reduces usefulness)
79
ondansetron
peri-operative N/V
80
scopolamine
peri-operative N/V and anticholinergic
| most potent at sedation and amnesia
81
glycopyrrolate
peri-operative anticholinergic
| most potent at decreasing secretions
82
dopamine
peri-operative CV support for hypotension
| B effect and renal preservation
83
nitroprusside
peri-operative CV support for hypertension
| vasodilator
84
trimethaphan
peri-operative CV support for HTN
| ganglionic blocker
85
anxiolysis
decrease apprehension
86
conscious sedation
protective reflexes maintained
independent maintenance of airway
response to physical/ verbal stimulation
87
deep or unconscious sedation
profound effect with loss of 1 or more of the following: protective relaxes, independent airway maintenance, or response to physical/ verbal stimulation
does NOT mean they are unconsciousness
transition into unconsciousness with additional drug application
88
general anesthesia
sensory, mental, reflex, motor blockade
| loss of ALL protective reflexes
89
general anesthesia
IV or inhalation: most control
| req. mechanical airway
90
Meyer-Overton Hypothesis
potency of anesthesia is proportional to lipid solubility
larger oil gas partition coefficient: more lipid soluble
91
minimum alveolar concentration (MAC)
concentrate non inspired gas required to render half of patients unconsciousness
lower MAC: more potent
92
Patient stages of inhalation anesthetic administration: BP, muscle tone, respiration, pupils
1. initial (due to?)
2. after unconsciousness
1. increased BP and muscle tone, pupil dilation, exaggerated respiration (removal of inhibitory neural pathways)
2. decreased respiratory function, CV function (decrease BP), loss of protective reflexes and muscle tone, pupil dilation
93
What generally precedes loss of pain in anesthesia?
| What is important to do when giving anesthesia related to this?
memory loss and perception loss (autonomics go after pain)
give ANALGESICS
94
2nd gas effect
NITROUS OXIDE
| causes 2nd gas to accumulate more quickly than it does on its own
95
diffusional hypoxia
NITROUS OXIDE
turn off anesthetic and large amount exits in exhale
must apply OXYGEN MASK
96
NMDA receptor
for stimulatory glutamate system
97
```
Effects of induction IV anesthetics
(thiopental, etomidate, ketamine, propofol)
1. CBF and ICP
2. respiratory function
3. CV
```
1. depress cerebral blood flow and ICP (exception: ketamine)
2. inhibitory (exception: ketamine)
CV
1. thiopental, propofol: increase HR, decrease CO and MAP
2. etomidate: no effects
3. ketamine: cardio stimulatory
98
flumazenil
benzodiazepine antagonist
99
neurolept-analgesia
pain relief and state of indifference (decrease anxiety)
can respond to command
add nitrous oxide to induce anesthesia
100
droperidol
neurolept-analgesia
| state of indifference, anti-emetic, anti-convulsant
101
atropine + morphine or meperidine
neurolept-analgesia
| prep for surgery: dry secretions and analgesia
102
malignant hyperthermia
MoA: intracellular Ca release for SR
HEAT, RIGIDITY, TACHYCARDIA/PNEA, ACIDOSIS, unexpected CARDIAC ARREST, increase end tidal CO2
SUCCINYLCHOLINE, VOLATILE anesthetics
genetic predisposition: RYANODINE receptor (RYR1)
Tx: DANTROLENE
103
dantrolene
repackages Ca into SR
Tx: malignant hyperthermia
CI: Ca channel blocker
104
ideal local anesthetic
lipophilic (pass membrane) and hydrophilic
| short onset, reversible, low toxicity
105
Order of sensitivity of nerves to nerve block
most: small myelinated and non-myelinated nerves
least: large myelinated
spontaneously active nerves: local anesthetics more effective
106
local anesthetics: ionized vs nonionized
1. pH of environment = pKa of drug
2. pH is 1 > pKa
3. pH is 2 > pKa
4. pH is 1
1. 50% of drug is nonionized
2. 90% of drug is nonionized
3. 99% of drug is nonionized
4. 90% of drug is ionized
5. 99% of drug is ionized
nonionized: can cross membrane
charged: can bind channel
inflammation: more acidic environment leads to inability of drug to cross membrane because it is ionized
107
Direction of nerve block and recovery
proximal to distal
108
1. signs of systemic toxicity with local anesthetics
| 2. AE of toxicity
1. ringing in ears, metallic taste, numb lip and tongue
| 2. CV depression, respiratory arrest, convulsions
109
How many mg/mL
1. 1% solution
2. 2% solution
3. 5% solution
4. 5.5% solution
members mean 1g/ 100mL
(% solution x 1000mg) / 100mL
OR
add a zero to the % number
1. 1000mg/ 100mL: 10mg/mL
2. 2000mg/100mL: 20mg/mL
3. 5000mg/100mL: 50mg/mL
4. 5500mg/100mL: 55mg/mL
110
How many mg/mL
1. 1: 1,000
2. 1: 10,000
3. 1: 100,000
4. 1: 200,000
numbers mean 1g/ (x)mL
(first number x 1,000mg) / (second number x 1mL)
1. 1000mg/1000mL: 1mg/mL
2. 1000mg/10,000mL: 0.1mg/mL
3. 1000mg/100,000mL: 0.01mg/mL
4. 1000mg/200,000mL: 0.005mg/mL
111
What determines
1. potency
2. time of onset
3. duration of action
4. metabolism
1. lipid solubility: increased means more potent
2. dissociation constant/ pKa: low pKa hastens onset
3. protein binding (increased affinity increases time bound to Na channel)
4. amide vs. ester linkage
112
methemoglobinemia
oxidized Fe causes reduced O2 carrying capacity
PRILOCAINE, BENZOCAINE
Sx: BLUE skin, SOB, lack of energy, headache
Tx: methylene blue or ascorbic acid
113
lidocaine-oxymetazoline
reduce vascular engorgement and provide analgesia
| use by otolaryngologist to aid in visualization of engorged nasal passage
114
epidural/spinal anesthesia
block is on fibers exiting cord (not the cord itself)
distribution depends on baricity (density compared to CSF) and patient orientation
increase temperature: increase spread
115
spinal anesthesia of
1. isobaric solution
2. hyperbaric solution
3. hypobaric solution
1. stays at level of injection
2. travels down with gravity
3. travels against gravity
depends on patient position
116
What should you keep in mind about injection technique of local anesthetics?
neutralize with Na Bicarb immediately before use to preserve drug stability
local anesthetics are acidic causing stinging so add base
117
What drugs can be given in intubation?
1. lidocaine: decrease ICP and bronchospasm
2. fentanyl: decrease sympathetic response
3. atropine: mitigate bradycardia response of SCh
4. vecuronium: mitigates ICP response of SCh
5. succinylcholine: NMB
6. sedative
118
ephedrine
peri-operative for CV support for hypotension
119
What do you give to someone that won't wake up from Sx?
reversal of most likely agent
1. narcotic of benzodiazepine antagonist
2. physostigmine to reverse Ach effects
other reasons: lidocaine, old age, NM agents (only if severe respiratory depression is this suspected)
120
signs of anaphylaxis
respiratory: cyanosis, wheeze
CV: arrest, tachycardia
cutaneous: flushing, edema, urticaria
