Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Apex > Unit 4 Pharmacology: IV Anesthetics > Flashcards

Unit 4 Pharmacology: IV Anesthetics Flashcards

(196 cards)

Start Studying
1
Q

What is the chemical name of propofol?

A

2,6-diisopropylphenol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the drug class of propofol?

A

Isopropylphenol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the formulation of propofol?

A

1% oil in water

  • soybean oil 10%
  • glycerol 2.25%
  • egg lecithin (yolk) 1.2%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the pKa of propofol?

A

11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What preservatives are used in propofol?

A

Diprivan : disodium edetate (EDTA)

Generics: metabisulfate OR benzyl alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What side effect can be caused by the preservative EDTA in propofol?

A

None, it is not an irritant to the bronchi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What side effect can occur from the preservative metabisulfate in propofol?

A

Can cause bronchospasm in patients with asthma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What side effect can occur from the additive benzyl alcohol in propofol?

A

In infants the benzyl alcohol can accumulate in the brain because they can break it down, but they can not conjugate it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the MOA of propofol?

A

Direct GABA-A agonist

  • increases Cl- conductance
  • leads to neuronal hyperpolarization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the adult induction dose of propofol?

A

1-2 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the adult infusion rate of propofol?

A

25-200 mcg/kg/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the induction dose that should be used for the elderly, debilitated or hypokalemic patient?

A

1-1.5 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the onset of propofol?

A

30-60 seconds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the duration of propofol?

A

5-10 minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When does brain concentration of propofol peak?

A

~ 1 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What causes reawakening with propofol use?

A

Redistribution out of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Propofol context sensitivity?

A

Pretty insensitive

XX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Clearance of propofol is by?

A

Liver : P450
-clearance exceeds liver blood flow

Extrahepatic metabolism : lungs (mostly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Propofol alpha 1/2 time? Beta 1/2 life?

A

Alpha 1/2 time : 2-8 minutes

Beta 1/2 life : 1-2 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Does propofol have an active metabolite?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the pKa of propofol?

A

11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Is propofol an acid or base?

A

Weak acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Propofol protein binding?

A

98%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Is propofol more ionized or non-ionized (with normal physiologic pH)?

A

More non-ionized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How long in an open bottle of propofol okay to use? Propofol in a syringe?
12 hours 6 hours
26
Does propofol cross the placenta?
Yes
27
Cardiovascular effects of propofol:
Decreased BP due to decreased tone and vasodilation Decreased SVR Decreased venous tone -> decreased preload Decreased myocardial contractility
28
Why does propofol decrease BP?
Decreased SNS and vasodilation
29
In what patients is the decrease in BP from propofol greater?
Geriatric patients | LV dysfunction
30
Why does CO decrease with propofol?
``` Decreases contractility (negative inotrope) Decreases venous tone which decreases preload ```
31
Why does propofol cause respiratory depression?
It shifts the CO2 response curve down and right (less sensitive to CO2) Inhibits hypoxic ventilatory drive
32
Does propofol cause bronchodilation?
No/maybe | Per Nagelhout: 0/⬆️
33
CNS effects of propofol:
Decreased cerebral oxygen consumption (CMRO2) Decreased cerebral blood flow Decreased intracranial pressure Decreased intraocular pressure Anticonvulsant properties Myoclonus may occur Few cases of it inducing seizures, but this is very rare
34
How can propofol make cloudy urine?
Increased Uris acid excretion - does not suggest renal impairment or infection
35
Why does propofol decrease cerebral perfusion pressure?
Due to the decrease in MAP
35
Does propofol contain antioxidant properties?
Yes - free radical scavenging properties
36
What is believed to be the cause of propofol infusion syndrome (PRIS)?
Propofol contains an increased level of long-chain triglycerides, which impairs oxidative phosphorylation and fatty acid metabolism, this starves cells of oxygen (particularly cardiac and skeletal muscle)
37
Why can propofol cause green urine?
From phenol exrection
38
What rate/dose is a risk factor for PRIS?
> 4mg/kg/hr (67mcg/kg/min)
39
How many days on propofol infusion is a risk factor for PRIS?
> 48 hours
40
What are other risk factors are there for PRIS besides rate and consecutive days infused?
``` Sepsis - inadequate oxygen delivery Catecholamine infusions High dose steroids Significant cerebral injury Children (FDA warning decreased occurrence) ```
41
Signs and symptoms of PRIS?
Acute refractory bradycardia that can lead to asystole AND at least one of the following: - metabolic acidosis (base deficit > 10 mmol/L) - Rhabdomylosis - Enlarged/fatty liver - Renal failure - HLD - lipemia may be an early sign
42
What CK results is a high risk for PRIS?
> 5,000
43
What is the treatment for PRIS?
``` Stop propofol Maximize gas exchange Cardiac pacing PDE inhibitors Glucagon ECMO and/or renal replacement therapy ```
44
What dose of propofol has an antipruritic effect? Antiemetic?
Antipruretic: 10mg - itching caused by opioids and cholestasis Antiemetic: 10-20 mg - can be used for PONV (infusion 10 mcg/kg/min)
45
What is the chemical name of Fospropofol?
Phosphono-O-methyl-2-6-diisopropylphenol
46
What is the class of Fospropofol?
Isopropylphenol
47
What is the formulation of fospropofol?
Aqueous solution
48
What benefits does the formulation of fospropofol have over propofol?
Prevents burning on injection | Doesn’t support microbial growth
49
What is the MOA of fospropofol?
It is a prodrug | It is metabolized by alkaline phosphatase into propofol
50
What is the induction dose of fospropofol?
6.5 mg/kg
51
What is the repeat dose for fospropofol? How often can it be re-dosed?
1.6 mg/kg | Not more than every 4 minutes
52
What is the onset of fospropofol?
5 - 13 minutes
53
What is the duration of fospropofol?
15 - 45 minutes
54
How is fospropofol cleared?
Since it is metabolized to propofol, the same as it. | Liver P450 enzymes plus extra hepatic metabolism (mostly lungs)
55
Does fospropofol have an active metabolite?
Fospropofol is a prodrug, and propofol is the active metabolite The formaldehyde is metabolized to formate and excreted in the urine
56
What is a “nasty” side effect of fospropofol?
Genital and anal burning
57
What is the chemical name of ketamine?
2-(o-Chloropheyl)-2 (methylamino) cyclohexanone hydrochloride
58
What class is ketamine?
Arylcyclohexylamine - a phencyclidine derivative
59
What is the formulation of ketamine?
Aqueous solution | It is a racemic mixture
60
What is the pKa of ketamine?
7.5
61
What is the MOA of ketamine?
NMDA receptor antagonist - antagonizes glutamate | Secondary receptors: opioid, MAO, serotonin, ME, muscarinic, Na+ channels
62
What dissociative effect does ketamine have?
It dissociates the thalamus (sensory) from the limbic system (awareness)
63
``` IV doses for Ketamine: Induction Maintenance Infusion Analgesia ```
Induction: 1 -2 mg/kg Maintenance: 1 - 3 mg/min Infusion: 1 - 3 mcg/kg/min (opioid sparing) Analgesia: 0.1 - 0.5 mg/kg
64
What is the IM dose for ketamine?
4 - 8 mg/kg
65
What is the PO dose for ketamine?
10 mg/kg
66
What is the onsets for ketamine? IV IM PO
IV: 30 - 60 sec IM: 2 - 4 minutes PO: variable
67
What is the duration of ketamine?
10-20 minutes
68
How is ketamine cleared?
Liver P450
69
Does ketamine have an active metabolite?
Norketamine | It is 1/3 - 1/5 the potency of ketamine
70
How is ketamine excreted?
Renal excretion
71
What are the CV effects of ketamine?
``` Increases SNS tone Increases CO Increases HR Increases SVR Increases pulmonary vascular resistance - caution with severe RV failure ```
72
What can you do if you want to use ketamine without activating the SNS?
Use subhypnotic dose - <0.5 mg/kg
73
What happens if ketamine is given to a patient with depleted cathecholamine stores (like sepsis or sympathetomy)
Ketamine is actually a myocardial depressant, with an intact SNS one will see the expected CV effects of ketamine. Without an intact SNS the myocardial depressant effects will be unmasked.
74
What are the respiratory effects of ketamine?
Bronchodilation Upper airway muscle tone and airway reflexes remain intact Maintains respiratory drive (brief period of apnea can occur) Does not significantly shift the CO2 response curve Increased oral and pulmonary secretions - Glyco helps
75
What are the CNS effects of ketamine?
``` Increased CMRO2 Increased cerebral blood flow Increased intracranial pressure Increased intraocular pressure Increased EEG activity - caution if Hx of seizures Nystagmus - caution with ocular sx Emergence delirium ```
76
How does emergence delirium from ketamine present, and how does the risk last?
Nightmares and hallucinations | Risk persists for up to 24 hours
77
What can you give to help prevent emergence delirium from ketamine? What works best?
Benzodiazepine | Midazolam is better than diazepam
78
What are 4 risk factors for emergence delirium from ketamine?
Age > 15 yrs Female Dose > 2mg/kg Hx of personality disorder
79
What type of pain does ketamine relieve better?
Somatic > visceral pain
80
How does ketamine stop wind-up pain?
Blocks central sensitization and wind-up in the dorsal horn
81
What opioid side effect can ketamine prevent?
Hyperalgesia
82
Chronic ketamine can cause:
Ulcerative cystitis
83
What IV anesthetic undergoes the least amount of protein binding? How much?
Ketamine - 12%
84
What is the chemical name for Etomidate?
R-1-methyl-1-(a-methylbenzyl) imidazole-5-carboxylate
85
What class is Etomidate?
Imidazole
86
What affect does pH have on Etomidate?
In an acidic pH -> imidazole ring opens -> increased water solubility In physiologic pH -> imidazole ring closes -> increases lipid solubility
87
What is the plasma protein binding % for Etomidate?
75%
88
What is the MOA of Etomidate?
GABA-A agonist
89
What is the induction dose for Etomidate?
0.2-0.4 mg/kg
90
What is the onset of Etomidate?
30 - 60 seconds
91
What is the duration of Etomidate?
5 - 15 minutes
92
How is Etomidate cleared?
Hepatic P450 enzymes plus plasma esterases
93
What causes the rapid awakening with Etomidate?
Redistribution NOT metabolism
94
Does Etomidate have an active metabolite?
No
95
What are the CV effects of Etomidate?
Minimal changes in HR, SV, or CO | SVR decreases which accounts for small reduction in BP
96
Does Etomidate block the SNS response to laryngoscopy?
No.
97
What are the respiratory effects of Etomidate?
Mild respiratory depression (less than propofol and barbiturates)
98
What are the CNS effects of Etomidate?
Decreased CMRO2 Decreased cerebral blood flow - cerebral vasoconstriction Decreased intracranial pressure Cerebral perfusion pressure remains stable
99
Define myoclonus
Involuntary skeletal muscle contractions, dystopia, or tremors
100
What is likely the cause of myoclonus with Etomidate?
An imbalance between excitatory and inhibitory pathways in the thalamocortical tract
101
Can Etomidate increase risk of seizure?
Etomidate can increase epileptiform (seizure-like) activity and possibly increase the risk for a seizure IF patient has a history of seizures
102
Which anesthetic agent increases mortality in patients with Addisonian crisis?
Etomidate
103
How does Etomidate causes adrenocortical suppression?
It inhibits 11-beta-hydroxylase and 17-alpha-hydroxylase | -cortisol and aldosterone synthesis are dependent on the enzyme 11-beta-hydroxylase
104
How long does a single dose of Etomidate suppress adrenocortical function?
5 - 8 hours (some books say up to 24 hours)
105
Due to the cause of adrenocortical suppression, in which patients should Etomidate be avoided?
Those reliant on the intrinsic stress response - sepsis or acute adrenal failure, they need all the cortisol they can muster
106
What side effect is more common with Etomidate than any other induction agent?
PONV (may be as high as 30-40%)
107
Barbiturates are derived from?
Barbiturates acid
108
How are the different types of barbiturates made, by doing what to the 6 carbon ring of barbiturate acid? What are they?
Thiobarbiturates: sulfur molecule in the second position (increases lipid solubility and potency) Oxybarbiturates: oxygen molecule in the second position Others: -methyl group on the nitrogen lowers seizure threshold and increases potency (methohexital) -phenyl group at the 5 carbon in cereals the anticonvulsant effect (phenobarbital)
109
What is the chemical name for Thiopental?
5-ethyl-5-(1-methylbutyl)-2-thiobarbituric acid
110
What is the formulation of Thiopental?
Water soluble
111
What is the pH of Thiopental? What benefit does this have?
9 - highly alkaline | No venous irritation or pain on injection
112
What is the MOA of Thiopental? What is the difference between a low/normal dose and high dose?
GABA-A agonist - depresses the reticular activating system in the brainstem. Low/normal dose: increases the affinity of GABA for its binding site High dose: directly stimulates the GABA-A receptor
113
What is the dose of Thiopental for adults? Children?
Adults: 2.5 - 5 mg/kg Kids: 5 - 6 mg/kg
114
What is the onset of Thiopental?
30 - 60 seconds
115
What is the duration of Thiopental?
5 - 10 minutes
116
How is Thiopental cleared?
Liver P450 enzymes
117
How is rapid wake up from Thiopental explained?
Redistribution NOT metabolism
118
What occurs with repeat dosing of Thiopental?
Tissue accumulation -> prolong wake up time + hang over effect
119
Does Thiopental have an active metabolite?
After normal dosing no | After high dose pentobarbital
120
CV effects of Thiopental?
Hypotension - primarily the result of venodilation and decreased preload, secondarily myocardial depression Histamine release -> hypotension, but short-lived Baroreceptor reflex is preserved so reflex tachycardia helps to restore CO
121
How does the hypotension caused by Thiopental compare to propofol?
Less hypotension than propofol
122
Respiratory effects of Thiopental?
Respiratory depression - shift CO2 response curve to the right Histamine release can cause bronchoconstrition, cause with asthma
123
CNS effects of Thiopental?
Decreased CMRO2 Decreased cerebral blood flow - cerebral vasoconstriction Decreased intracranial pressure - used to tx intracranial HTN Decreased EEG activity - can cause burst suppression and/or isoelectric EEG Neuroprotection with focal ischemia but not global ischemia
124
What is Porphyria?
Group of diseases in which excessive porphyrins are formed and accumulate in the tissues. It reflects deficiencies in heme synthesis causing painful demyelination of peripheral and cranial nerves.
125
What are the 2 classes of porphyria?
Acute - inducible | Chronic - non-inducible or cutaneous
126
What is the most common and dangerous type of inducible porphyria?
Acute intermittent porphyria
127
Acute intermittent porphyria is made worse by what 4 things?
Stimulation of ALA synthase Emotional stress Prolonged NPO status CYP 450 induction
128
What is the most common sign/symptom of acute intermittent porphyria and which also typically occurs first?
Severe abdominal pain
129
What are the signs/symptoms of acute intermittent porphyria?
GI: severe abdominal pain, N/V CNS: anxiety, confusion, seizures, psychosis, coma PNS: skeletal muscle weakness (risk of respiratory muscle failure), bulbar weakness (risk of aspiration)
130
What drugs should be avoided with porphyria?
``` Barbiturates Etomidate Ketamine Ketorolac Amiodarone CCB (but not all) Birth control pills ```
131
What are 4 important anesthetic management points with porphyria?
Liberal hydration Glucose supplementation (reduces ALA synthase activity) Heme arginate (reduces ALA synthase activity) Prevention of hypothermia
132
What common agents are safe to administer with porphyria?
``` Volatile agents N2O NMBs and their reversal agents Narcotics Midazolam Ondansetron Vasopressors BB ```
133
Is regional anesthesia contraindicated with porphyria?
No. But most avoid it since it may be difficult to distinguish block-related complications from an acute porphyria attack
134
What happens if Thiopental is injected intra-arterial?
Intense vasoconstriction crystal formation (occludes blood flow) Inflammation Tissue necrosis
135
What do you do if Thiopental is injected intra-arterial?
Vasodilator: phentolamine or pheoxybenzamine Sympathectomy: Stellate ganglion block or brachial plexus block
136
What IV agent is the gold standard for electroconvulsive therapy?
Methohexital
137
What is the induction dose for Methohexital?
1 - 1.5 mg/kg
138
All barbiturates are metabolized by what? Except for which one?
Liver P450 enzymes Phenobarbital - excreted unchanged in the urine
139
Which anesthetic agent produces sedation that most closely resembles natural sleep?
Dexmedetomidine
140
What is the chemical name of dexmedetomidine?
(S)-4-[1-(2,3-Dimethylphenyl)ethyl]-1H-imidazole monohydrochloride
141
What class is dexmedetomidine?
Imidazole
142
What is the formulation of dexmedetomidine?
Water soluble
143
What is the pKa of dexmedetomidine?
7.1
144
What is the plasma protein binding % of dexmedetomidine?
94%
145
What is the MOA of dexmedetomidine?
Alpha-2 agonist -> decreases cAMP -> which inhibits the locus coeruleus in the pons (sedation)
146
What is the loading dose of dexmedetomidine? Maintenance infusion?
Loading dose: 1 mcg/kg over 10 minutes | Infusion: 0.4 - 0.7 mcg/kg/hr
147
What is the onset of dexmedetomidine?
With loading dose 10 - 20 minutes
148
What is the duration of dexmedetomidine?
After infusion is stopped 10 - 30 minutes
149
How is dexmedetomidine cleared?
Liver P450 enzymes
150
Does dexmedetomidine have an active metabolite?
No
151
CV effects of dexmedetomidine?
Bradycardia | Hypotension
152
Explain what happens in relation to BP when dexmedetomidine is given
Rapid administration of dexmedetomidine can cause HTN (alpha-2 stimulation in the vasculature -> vasoconstriction). This direct effect occurs before the centrally mediated reduction in SNS tone. So once the CNS effects kick in, they over power the peripheral effects.
153
Respiratory effects of dexmedetomidine?
Does not cause respiratory depression No change in oxygenation No change in blood pH No change in the slope of the CO2 response curve
154
CNS effects of dexmedetomidine?
Decreases CBF No change in CMRO2 - there is uncoupling of CBF and CMRO2 No change in ICP
155
How does dexmedetomidine produce sedation?
Sedation is the result of decreased SNS tone and decreased level of arousal
156
Does dexmedetomidine provide amnesia?
It does not provide reliable amnesia
157
How does dexmedetomidine produce analgesia?
By alpha-2 stimulation in the dorsal horn of the spinal cord - this decreases substance P and glutamate release
158
What effect does dexmedetomidine have on shivering?
It impairs thermoregulatory response, so it produces anti shivering effect
159
What effect does dexmedetomidine have on evoked potentials?
It does not impair evoked potentials
160
What benefits does dexmedetomidine have for use with kids?
It reduces incidence of emergence delirium in kids | The nasal and buccal route have high degree of bioavailability making it useful for preop sedation in kids
161
What is the dose for preop sedation in kids? When should it be given?
3 - 4 mcg/kg | 1 hour prior to surgery
162
What is the chemical name of midazolam?
8-chloro-6-(2-flurophenyl)-1-methyl-4 H-imidazo[1,5-a][1,4]benzodiazepine
163
What class is midazolam?
Benzodiazepine
164
What is the formulation of midazolam?
Imidazole ring
165
What affect does pH have on midazolam?
Acidic pH -> imidazole ring opens -> increases water solubility Physiologic pH -> imidazole ring closes -> increase lipid solubility
166
What preservatives are used in midazolam?
0.01% disodium edetate | 1% benzyl alcohol
167
What is the MOA of midazolam?
GABA-A agonist -> increases frequency of channel opening -> neuronal hyperpolarization
168
How are benzodiazepines different from other GABA-A agonists?
Most GABA-A agonists increase channel open time | Benzodiazepines increase open frequency
169
What is the IV sedation dose of midazolam?
0.01 - 0.1 mg/kg
170
What is the IV induction dose of midazolam?
0.1 - 0.4 mg/kg
171
What is the PO sedation in children dose for midazolam?
0.5 - 1.0 mg/kg
172
What is the bioavailability of PO midazolam?
50% due to significant first pass metabolism
173
What is the onset of midazolam?
30 - 60 seconds
174
What is the duration of midazolam?
20 - 60 minutes
175
How is midazolam cleared?
Liver P450 enzymes | Intestine P450 enzymes
176
Does midazolam have an active metabolite?
1-hydroxmidazolam
177
What is the potency of 1-hydroxymidazolam?
0.5 x potency of midazolam and is rapidly conjugated into an inactive compound
178
What condition prolongs the effect of 1-hydroxymidazolam?
Renal failure
179
CV effects of midazolam?
Sedation dose: minimal effects | Induction dose: decreased BP and SVR
180
Respiratory effects of midazolam?
Sedation dose: minimal effects | Induction dose: respiratory depressant
181
Even when using the sedation dose for midazolam, what can potential respiratory depression?
Opioids
182
What patients are more sensitive to the respiratory depressant effects of midazolam?
COPD
183
CNS effects of midazolam?
Sedation dose: minimal effects on CMRO2 and CBF Induction dose: decreases CMRO2 and CBF Anterograde amnesia Anticonvulsant Anxiolysis Spinally mediated skeletal muscle relaxation (antispasmodic)
185
What is the elimination t 1/2 of diazepam?
43 hours
186
Why does diazepam remain in the body for such a long time?
It undergoes enterohepatic recirculation
187
How long can lorazepam’s amnestic action persist?
Up to 6 hours
188
Why is lorazepam not the best choice for anticonvulsant?
Slow onset
189
Put midazolam, diazepam and lorazepam into relative potency greatest to least
Lorazepam > midazolam > diazepam
190
What is added to diazepam and lorazepam to enhance water solubility that is not needed in midazolam?
Propylene glycol - this causes venous irritation (diazepam > lorazepam)
190
What is done after the initial dose of flumazenil?
It is titrated in 0.1 mg increments every 1 minute
191
What is Flumezenil?
A competitive antagonist of the GABA-A receptor
193
What is the duration of flumazenil?
30 - 60 minutes
194
What is the initial dose of flumazenil?
0.2 mg IV
195
What effect does flumazenil have on reversing the sedative and amnestic effects of benzodiazepines?
It tends to reverse the sedative effects more than the amnestic effects
196
What is the plasma protein binding of: Midazolam Diazepam Lorazepam
Midazolam: 94% Diazepam: 98% Lorazepam: 90%

Apex (46 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions