CV Drugs II Flashcards
(88 cards)
1
Q
Ephedrine Class
A
- NT Releaser
- Alpha- & Beta-Adrenergic Receptor Agonist
2
Q
Ephedrine MOA
A
- direct –> acts directly at alpha and beta adrenergic receptors to create effect
- indirect –> acts to increase the amount of NT released (specifically NE)
3
Q
Ephedrine PK/PD
A
DOA: 15-60 min
-DOA prolonged in elderly
4
Q
Ephedrine Dose/Route
A
IV bolus: 0.1-0.2 mg/kg OR 5-25 mg
*can give in 5 mg increments
5
Q
Ephedrine Clinical uses
A
hypotension
6
Q
Ephedrine Effects/Considerations
A
can cause tachyphylaxis which depletes stores of catecholamines with repeated doses
7
Q
Phenylephrine Class
A
Alpha Adrenergic Agonist
8
Q
Phenylephrine MOA
A
- direct acting only
- binds to the alpha adrenergic receptor and exerts same effect as endogenous catecholamine
9
Q
Phenylephrine PK/PD
A
DOA: 5-10 min
10
Q
Phenylephrine dose/route
A
IV bolus: 50-200 mcg
IV infusion: 20-100 mcg/min
11
Q
Phenylephrine clinical uses
A
- hypotension
- nasal intubation or NP tube placement as nasal spray to vasoconstrict –> decrease bleeding risk
12
Q
Alpha Adrenergic Antagoinst Drugs
A
Phentolamine
Prazosin
Yohimbine
Phenoxybenzamine
13
Q
Alpha Adrenergic Antagoinst MOA
A
- bind selectively to alpha receptors and interfere with ability of catecholamines to cause a response
- phentolamine, prazosin, yohimbine = competitive antagonism
- phenoxybenzamine = covalent bond
14
Q
Alpha Adrenergic Antagoinst clinical uses
A
- HTN
- BPH (benign prostatic hypertrophy)
- pheochromocytoma (non-selective agents)
15
Q
Alpha Adrenergic Antagoinst effects/considerations
A
CV Effects:
-alpha 1 –> decreased PVR, decreased BP, postural hypotension (d/t failure of venoconstriction upon standing
-alpha 2 –> increases NE release from nerve terminals, resultant tachycardia from stimulation of beta receptors
GU effects – blockade in prostate and bladder cause muscle relaxation and ease micturition
-miosis
-increased nasal congestion
16
Q
Phenoxybenzamine Class
A
Non-selective Alpha-Adrenergic Antagonist
17
Q
Phenoxybenzamine MOA
A
- covalent bond to alpha receptor
- non-selective but higher affinity for alpha 1 vs alpha 2
18
Q
Phenoxybenzamine PK/PD
A
-pro-drug (i.e., inactive until something in body activates it
Onset: 1 hour
E1/2: 24 hrs
19
Q
Phenoxybenzamine Dose/Route
A
PO: 0.5-1.0 mg/kg (preop for BP control for pheo)
20
Q
Phenoxybenzamine Clinical Uses
A
- preop for patients with pheochromocytoma (PO)
- potential use for patients with Raynaud’s
21
Q
Phenoxybenzamine Effects/Considerations
A
- decreased SVR, vasodilation
- less tachycardia (due to less alpha2)
22
Q
Phentolamine Class
A
Non-selective Alpha-Adrenergic Antagonist
23
Q
Phentolamine MOA
A
non-selective, equal affinity for alpha1 and alpha2
24
Q
Phentolamine Dose/Route
A
IV: 30-70 mcg/kg
SubQ: 2.5-5 mg
25
Phentolamine Clinical Uses
- intraoperative management of HTN emergencies (Pheo manipulation or autonomic hyperreflexia)
- extravascular admin of sympathomimetic agents (subQ to minimize necrosis)
26
Phentolamine Effects/Considerations
- peripheral vasodilation and a decrease in SVR
| - reflex mediated and alpha2 associated increase in HR and CO
27
Prazosin Class
Selective Alpha1-Adrenergic Antagonist
28
Prazosin MOA
selective for alpha1
29
Prazosin Clinical Uses
- preop prep for pheo
- essential HTN (in combo with thiazides)
- decrease afterload in pt with HF
- Raynaud phenomenon
30
Prazosin Effects/Considerations
- less likely to cause tachycardia
| - dilates both arterioles and veins
31
Yohimbine Class
Selective Alpha2-Adrenergic Antagonist
32
Yohimbine MOA
- selective for alpha 2
- higher affinity for alpha2 vs alpha1
- increases release of NE from post-synaptic neuron
33
Yohimbine Clinical Uses
- orthostatic hypotension
| - impotence
34
Terazosin & Tamsulosin Class
Selective Alpha1-Adrenergic Antagonist
35
Terazosin & Tamsulosin MOA
long acting selective alpha 1a
36
Terazosin & Tamsulosin Clinical Uses
BPH
37
Terazosin & Tamsulosin effects/considerations
- biggest concern orthostatic hypotension
- Tamsulosin HIGHLY selective for receptors in urogenital tract so less of a problem with orthostatic hypotension but can still occur
38
Beta-Adrenergic Receptor Antagonist Drugs
```
Propranolol
Metoprolol
Atenolol
Esmolol
Timolol
Nadolol
Betaxolol
Labetalol
```
39
Beta-Adrenergic Receptor Agonist MOA
- derivatives of isoproterenol, so possess some sympathomimetic effects
- selective binding to beta receptors
- competitive and reversible inhibition – large doses of agonists will completely overcome antagonism
- chronic use – associated with up-regulation (if stop, exaggerated respose to SNS)
40
Beta-Adrenergic Receptor Antagonist clinical use
- HTN
- management of angina
- decrease mortality in treatment of post MI patients
- used periop and preop for patients at risk for MI
- suppression of tachyarrhythmias
- prevention of excessive SNS activity
41
Beta-Adrenergic Receptor Antagonist CV Effects
- bradycardia
- decreased contractility
- decreased conduction velocity
- improve O2 supply/demand balance
- vasoconstriction in skeletal muscles, PVD symptoms increased
42
Beta-Adrenergic Receptor Antagonist resp effects
- bronchoconstriction
| - can provoke bronchospasm in patients with asthma or COPD
43
Beta-Adrenergic Receptor Antagonist effect on JG cells
decreased renin release; indirect way of decreasing BP
44
Beta-Adrenergic Receptor Antagonist effect on pancreas
decreased stimulation of insulin release by epi/NE at B2; masks symptoms of hypoglycemia at B1 (bc no increased HR)
45
Beta-Adrenergic Receptor Antagonist effect on eyes
decreased IOP, especially in glaucoma due to decreased aqueous humor production
46
Beta-Adrenergic Receptor Antagonist other effects/considerations
- chronic use decreased concentration of HDLs increase risk for CAD
- distribution of extracellular potassium-inhibit uptake of potassium into sk muscles
- interaction with anesthetics decrease BP with induction agents
- nervous system fatigue, lethargy
- N/V/D
47
Beta-Adrenergic Receptor Antagonist relative contraindications
pre-existing AV heart block or HF; RAD, DM (without BG monitoring), hypovolemia
48
Propranolol Class
Non-selective Beta Blocker
49
Propranolol MOA
about equal for beta1 and beta2
50
Propranolol PK/PD
- extensive 1st pass with oral admin (90-95%)
- protein bound (90-95%)
- metabolized in liver
- E1/2 2-3 hours
- increased in low hepatic blood flow states
- decreased clearance of amide Las due to decrease in hepatic blood flow inhibiting metabolism in liver – risk of systemic toxicity of LAs
51
Propranolol dose/route
IV bolus: 0.05 mg/kg OR 1-10 mg (give slowly 1 mg q 5 min)
52
Propranolol effects/considerations
-beta1 --> decreased HR and contractility
-beta2 --> increased vascular resistance
-decreased clearance of amide local anesthetics (particularly bupivacaine)
-decreased pulmonary clearance of fentanyl
-Goal HR 55-60bpm
CV Effects:
-decreased HR, contractility, CO (especially prominent during exercise and sympathetic outflow)
-increased PVR, increased coronary vascular resistance
-decreased MVO2
-reduction in renin release
53
Metoprolol Class
Beta 1 Selective Blocker
54
Metoprolol MOA
selective for beta 1, selectivity is dose related
55
Metoprolol PK/PD
- 60% first pass effect
- metabolized in liver
- IV onset 3 min
- E1/2 3-4 hrs
56
Metoprolol dose/route
PO: 50-400 mg
| IV bolus: 1-15 mg
57
Metoprolol clinical use
benefit for patients with COPD, asthma, lung disease
58
Metoprolol effects/considerations
- inotropic and chronotropic depressant
| - beta 2 receptors remain intact (bronchial dilation, vasodilation, metabolic effects)
59
Atenolol Class
Beta1 selective receptor blocker
60
Atenolol MOA
most selective for beta1
61
Atenolol PK/PD
- E1/2 7-6 hours
- not metabolized in liver
- excreted via renal system, E1/2 increased markedly in patients with renal disease
62
Atenolol clinical use
- advantageous for those who need beta 2 receptor activity
| - oral to treat HTN
63
Atenolol effects/considerations
- least CNS effects
| - longer lasting antihypertensive effects
64
Esmolol (breviblock) class
Beta 1 Selective Blocker
65
Esmolol PK/PD
- rapid onset and short DOA
- onset 60 seconds
- E1/2 9 min
- DOA 10-30 min
- metabolized by plasma esterase (less than 1% drug excreted in urine unchanged); not same as esterases responsible for succ
- poor lipid solubility
66
Esmolol clinical use
- used for treatment of HTN and tachycardia associated with laryngoscopy
- useful in treating hyperdynamic effects of pheochromocytoma, thyrotoxicosis, thyroid storm
67
Timolol class
non-selective beta-blocker
68
Timolol clinical use
tx of glaucoma – decreases IOP by decreasing production of aqueous humor
69
Timolol effects/considerations
- decreased BP
- decreased HR
- increased airway resistance
70
Nadolol class
Non-Selective Beta Blocker
71
Nadolol PK/PD
- no significant metabolism
- renal/biliary elimination
- E1/2 20-40 hours
72
Nadolol dose
1x daily
73
Betaxolol class
Beta 1 Cardio Selective Blocker
74
Betaxolol PK/PD
-E1/2 11-22 hours
75
Betaxolol dose
1x daily
76
Betaxolol clinical use
- tx of HTN
| - topical for glaucoma
77
Betaxolol effects/considerations
- less risk of bronchospasm than timolol
| - good choice for asthmatics with glaucoma
78
Labetolol Class
Combined Non-Selective Antagonist
79
Labetolol MOA
- alpha1, beta1, beta2
- IV beta to alpha blockade 7:1
- PO beta to alpha blockade 3:1
80
Labetolol PK/PD
- metabolism conjugated with glucuronic acid
- >5% of drug recovered unchanged in urine
- E1/2 5-8 hrs; prolonged in liver disease
- not affected by renal dysfunction
81
Labetolol dose/route
IV dose: 0.1-0.5 mg/kg (small increments)
| -usually 5mg at a time for mild HTN in OR
82
Labetolol clinical uses
- mild HTN in OR
- hypertensive crisis
- can be used in hypotensive technique without an increased HR
83
Labetolol effects/considerations
- max drop in BP 5-10 min after IV admin
- decreases systemic BP (alpha1) with attenuated reflex tachy (beta2)
- decreased HR, SVR, HR
- CO not affected
- can cause orthostatic hypotension, bronchospasm, heart block, CHR, bradycardia
84
Clonidine & Dexmedetomidine Class
Alpha 2 Receptor Agonist
85
Clonidine & Dexmedetomidine MOA
- reduce sympathetic outflow from vasomotor centers in brainstem; centrally acting selective partial alpha2 adrenergic agonist
- site of action --> CNS non-adrenergic binding sites and alpha2 receptor agonism
86
Clonidine & Dexmedetomidine PK/PD
- avail as PO or transdermal patch
| - 50/50 hepatic metabolism and renal excretion
87
Clonidine & Dexmedetomidine clinical use
- HTN
- induce sedation
- decrease anesthetic requirements
- improve peri-op hemodynamics
- analgesia
88
Clonidine & Dexmedetomidine effects/considerations
- BP reduction from decreased CO due to decreased HR and peripheral resistance
- rebound HTN with abrupt cessation
- SE --> bradycardia, sedation, xerostomia, impaired concentration, nightmares, depression, vertigo, EPS, lactation in men
- withdrawal syndrome --> occurs with doses of >1.2 mg/day; occurs 18 hours after acute discontinuation of drug; lasts 24-72 hrs; treatment of rectal or transdermal clonidine
