Sympatholytics, Antiarrythmics, Inotropes Flashcards
(129 cards)
1
Q
What are sympatholytics?
A
Typically adrenergic antagonists
Their goal is to reduce SNS stimulation, most work postsynaptically.
2
Q
Define inotropy.
A
Contractility
3
Q
What type of receptors are Gs receptors?
A
Stimulatory (beta-1 and beta-2 receptors)
4
Q
What enzyme is activated by Gs receptors?
A
Adenylyl cyclase
5
Q
What is the second messenger for Gs receptors?
A
Cyclic adenosine monophosphate (cAMP)
6
Q
What type of receptors are Gi receptors?
A
Inhibitory (alpha-2 receptors)
7
Q
What do Gq receptors catabolize?
A
Phospholipids
8
Q
Which enzyme is activated by Gq receptors?
A
Phospholipase C (PLC)
9
Q
What are the second messengers for Gq receptors?
A
- Diacylglycerol (DAG)
- Inositol triphosphate (IP3)
- Protein kinase C (PKC)
10
Q
List common types of sympatholytics.
A
- Alpha blockers
- Beta blockers
- Calcium channel blockers
11
Q
List common types of antiarrhythmics.
A
- Beta blockers
- Calcium channel blockers
- Potassium channel blockers
- Sodium channel blockers
12
Q
What is the action of alpha blockers?
A
Interfere with ability of catecholamines (epi, NE) to stimulate an alpha response (vasoconstriction)
13
Q
What is Phenoxybenzamine?
A
Nonselective alpha (A1, A2) blocker, noncompetitive (covalent bond)
14
Q
What are the indications for Phenoxybenzamine?
A
Pheochromocytoma
15
Q
How long does it take for Phenoxybenzamine to fully control hypertension?
A
Several weeks (2-10 weeks)
16
Q
What is the half-life of Phenoxybenzamine?
A
18-24 hours
17
Q
What is the duration of action for Phenoxybenzamine?
A
3-4 days
18
Q
What is the oral dose range for Phenoxybenzamine?
A
0.5-1mg/kg
19
Q
What is Phentolamine?
A
Nonselective (A1, A2) blocker, competitive
20
Q
What are the indications for Phentolamine?
A
- Pheochromocytoma
- Extravasation of vasoconstrictors
21
Q
What is the duration of action for Phentolamine?
A
10-15 minutes
22
Q
What is the IV bolus dose for Phentolamine?
A
30-70 mcg/kg
23
Q
What are the selective alpha blockers mentioned?
A
- Prazosin
- Doxazosin
- Tamsulosin
- Terazosin
24
Q
What is the indication for Tamsulosin?
A
BPH
25
What is the normal function of alpha-2 stimulation?
Decrease in presynaptic NE release, centrally causes sedation
26
What is the effect of alpha-2 agonists?
Decrease the release of NE, reducing sympathetic outflow
27
What is Yohimbine?
Selective A2 antagonist
28
What are the side effects of Yohimbine?
* Tremor
* Tachycardia
* Hypertension
* Dissociation
29
What do beta blockers prevent?
SNS (catecholamine) action on the heart (B1) and smooth muscles of the blood vessels and airway
30
What class of antiarrhythmic are beta blockers?
Class 2
31
What is the action of beta blockers on cardiac action potential?
Action on phase 4
32
List indications for beta blockers.
* Hypertension
* Angina
* Acute coronary syndrome/ischemia
* Arrhythmia suppression
* CHF
33
What should not be done prior to surgery regarding beta blockers?
Do not have patients stop beta blockers prior to surgery – may have rebound effect
34
What are the side effects of beta blockers?
* Bradycardia
* Asystole
* Inhibition of gluconeogenesis (hypoglycemia)
* Bronchoconstriction (B2 blockers)
35
What are the selective B1 blockers?
* Bisoprolol
* Esmolol
* Atenolol
* Metoprolol
36
What does the ratio 30:1 indicate in Metoprolol?
B1:B2 receptor affinity
37
What are the nonselective beta blockers?
* Carvedilol
* Propranolol
* Labetalol
* Nadalol
* Sotalol
* Timolol
38
What is the half-life of Nadalol and Pindolol?
20-40 hours
39
What are the long-term effects of beta blockers?
* Alteration in lipoprotein and triglyceride levels
* Related alopecia
* Myopathy
* Thrombocytopenia
40
What is the dose for Metoprolol IV?
2.5-5mg Q5min IVP
41
What is the PO dose range for Metoprolol?
12.5-100mg BID (50-150 mg daily ER)
42
What is the onset time for Metoprolol?
<1 min
43
What is the peak time for Metoprolol?
20 min
44
What is the duration of action for Metoprolol?
5-8 hours
45
What is Esmolol's mechanism of metabolism?
Metabolized by plasma ester hydrolysis
46
What is the IV concentration for Esmolol?
10mg/mL
47
What is the dose range for Esmolol infusion?
50-300 mcg/kg/min infusion
48
What is Atenolol's dose range?
50-200 mg/day PO
49
What is Labetalol's A:B ratio?
1:3 PO and 1:7 IV
50
What is the first line treatment for pregnancy-related hypertension?
Labetalol
51
What is Propranolol's lipophilicity?
Very lipophilic, crosses BBB
52
What is the dose range for Propranolol?
40-360 mg/day PO in divided doses
53
What is the primary effect of Carvedilol?
Nonselective B1/B2 and selective A1
54
What is the half-life of Carvedilol?
7-10 hours
55
What are the signs and symptoms of beta blocker overdose?
* Bradycardia
* Dysrhythmias
* Hypotension
* Decreased cardiac output that can progress to cardiogenic shock
56
What is the gold standard treatment for beta blocker overdose?
Glucagon
57
How does glucagon work in beta blocker overdose?
Increases adenylate cyclase activity without first stimulating the beta receptor
58
What is the dose range for glucagon in beta blocker overdose?
1 to 10 mg IV depending on severity of symptoms
59
What is required for CV support in beta blocker overdose?
Calcium, epinephrine, pacing
60
What is pheochromocytoma?
Adrenal medulla tumor that leads to increased Epi/NE levels
61
What is the diagnostic test for pheochromocytoma?
Testing for catecholamine byproducts (HVA, VMA) in urine or serum
62
What is the order of blockade for treating pheochromocytoma?
Alpha blockade must be instituted BEFORE beta blockade
63
What are the classes of antiarrhythmic medications?
* Na Channel Blockers
* K Channel Blockers
* Calcium Channel Blockers
64
How are Na channel blockers classified?
As Moderate (A), Weak (B), or Strong (C) action on the sodium channel based on dissociation
65
What do sodium channel blockers do?
Delay the point at which Na+ channels recover from an inactivated state, increasing the effective refractory period (ERP)
66
List examples of Class A sodium channel blockers.
* Quinidine
* Procainamide
67
What is an example of a Class B sodium channel blocker?
Lidocaine
68
What is an example of a Class C sodium channel blocker?
Flecainide
69
What is the action of potassium channel blockers?
Alter phase 3 of the cardiac action potential by increasing action potential duration
70
What is Amiodarone classified as?
Group 3 antiarrhythmic
71
What is the IV loading dose of Amiodarone?
150 mg over the first 10 minutes (15 mg/min)
72
What is the maintenance infusion for Amiodarone?
540 mg over the remaining 18 hours (0.5 mg/min)
73
What is the half-life of Amiodarone?
29 days
74
What risk does Amiodarone pose regarding thyroid function?
Can cause Amiodarone Induced Thyrotoxicosis (AIT)
75
What are the potential thyroid states caused by Amiodarone?
* Hyperthyroid
* Hypothyroid
76
What tests are used for diagnosing thyroid issues related to Amiodarone?
* T3
* T4
* TSH
77
What is the role of renin in the RAAS system?
Stimulates the conversion of angiotensinogen to angiotensin I
78
What does ACE convert angiotensin I to?
Angiotensin II
79
What effect does angiotensin II have on the autonomic ganglia?
Facilitates NE release and prevents its reuptake at nerve terminals
80
List classes of medications that target renal function in hypertension.
* ACE inhibitors
* Angiotensin Receptor Blockers (ARBs)
* Thiazide Diuretics
* Potassium Sparing Diuretics
* Aldosterone antagonists
81
What is the suffix for ACE inhibitors?
-pril
82
What is the suffix for Angiotensin Receptor Blockers (ARBs)?
-sartan
83
What do ACE inhibitors do?
Decrease conversion of angiotensin I to angiotensin II
84
What is the effect of ACE inhibitors on AT1 receptors?
Resulting in reduced vasoconstrictor effects, aldosterone secretion, and sympathetic activation
85
What is HCTZ?
Hydrochlorothiazide, a thiazide diuretic
86
Name two Potassium Sparing Diuretics.
* Triametrene
* Amiloride
87
What are Aldosterone antagonists?
Medications that block the effects of aldosterone, such as Spirinolactone
88
What is the primary action of Angiotensin Converting Enzyme (ACE) Inhibitors?
Decrease conversion of angiotensin I to angiotensin II
89
How do ACE inhibitors affect aldosterone secretion?
They inhibit aldosterone secretion
90
What is a common side effect of increased bradykinin production from ACE inhibitors?
Cough
91
What suffix is commonly associated with ACE inhibitors?
-pril
92
What do Angiotensin Receptor Blockers (ARBs) do?
Block the vasoconstrictive actions of Angiotensin on the AT1 receptor
93
Do ARBs inhibit the breakdown of bradykinin?
No
94
Which trial recommended holding ACE inhibitors or ARBs before surgery?
POISE trial
95
What is the 1st line treatment for ACEi/ARB related vasoplegia?
Vasopressin
96
What pathway does Nitric Oxide (NO) stimulate for vasodilation?
cGMP Pathway
97
What does Methylene Blue do in relation to Nitric Oxide?
Acts as a nitric oxide scavenger and vasoconstrictor
98
What is the primary effect of Sodium Nitroprusside?
Arterial and venous dilation
99
What is a significant risk of prolonged Sodium Nitroprusside administration?
Cyanide toxicity
100
What is the elimination half-life of Nitroglycerin?
1-2 minutes
101
What is the primary action of Adenosine?
Stimulates NO production and relaxes smooth muscle
102
What is the mechanism of action of Digoxin?
Inhibits Na/K pump activity
103
What are the signs of Digoxin toxicity?
* Nausea
* Heart block
* Bradycardia
104
What is the therapeutic range of Digoxin?
Narrow therapeutic range
105
What type of medication is Milrinone?
Phosphodiesterase inhibitor
106
What is the primary indication for Calcium Chloride?
Low serum calcium levels
107
What is Levosimendan known as?
Calcium Sensitizer
108
What are the common side effects of Fenoldopam?
* Reflex tachycardia
* Headache
* Flushing
109
What are the two main effects of Calcium inotrope?
* Increases blood pressure
* Inotropic activity
110
What is the primary action of Phosphodiesterase Inhibitors?
Competitive inhibition of phosphodiesterase enzymes
111
What is the main use of PDE5 inhibitors?
Erectile dysfunction and pulmonary hypertension
112
Name a common side effect of Sodium Nitroprusside.
Metabolic acidosis
113
What is the mechanism of action of Hydralazine?
Direct systemic arterial vasodilator
114
What is a common effect of Nitroglycerin?
Reduces preload and myocardial demand
115
Fill in the blank: The main smooth muscle vasodilator in normal endothelium is _______.
Nitric Oxide
116
True or False: ARBs are used in perioperative medicine.
False
117
What is the primary action of a D1 receptor agonist like Fenoldopam?
Arterial dilation through increasing levels of cAMP
118
What is the duration of action for Levosimendan?
Depends on timing of administration
119
What is the recommended treatment for cyanide toxicity from Sodium Nitroprusside?
* 100% FiO2
* NaHCO3 for acidosis
* Sodium thiosulfate
* Methylene blue
* Hydroxocobalamin
120
Metoprolol
2.5-5mg IVP q5min
121
Esmolol (bolus and infusion)
0.5-1mg/kg
50-300mcg/kg/min
122
Labetelol
0.1-0.5 mg/kg q5-10 min. (often 5-20mg)
123
Propranolol
40-360mg/day PO
124
Amiodarone (loading and maintenance)
150 mg over 10 min
360 mg over next 6 hrs
125
Diltiazem (IVB and PO)
0.25-0.35mg/kg IV, 60-90mg PO q8h
126
Nicardipine
5-15mg/h infusion
127
Clevidipine
start @ 1-2mg/h (double dose q90sec until target BP) (max 32mg/h)
128
Milrinone
0.375-0.75mcg/kg/min
129
