Cardiovascular Week 2 Flashcards
What are 5 alpha antagonists?
- clonidine
- phenoxybenzamine
- phentolamine
- prazosin
- sildenafil
What are 6 beta antagonists?
- Atenolol
- Carvedilol
- Esmolol
- Labetalol
- Metoprolol
- Propanolol
What type of drug is used to treat
- pheochromocytoma
- hypertensive emergencies
- chronic HTN
- erectile dysfunction
alpha blockers
What type of drug is used to treat
- HTN
- ischemic heart disease
- cardiac arrhythmias
- heart failure
beta blockers
How do ACEi treat HTN?
decrease total body volume
How do ARBs treat HTN?
decrease total body water
What 6 drugs or class of drugs treat HTN by manipulating vascular tone?
- Ca channel blockers
- K channel openers
- Endothelin receptor antagonists
- Hydralazine
- Alpha 1 antagonists (clonidine)
- Beta antagonists
What does activation of a1 cause?
- vasoconstriction
- relaxation of the GI tract
Where are a1 receptors found?
presynaptic
vasculature
heart
glands
gut
Where are a2 receptors found & what do they do?
presynaptic
- peripheral vascular smooth muscle
- coronaries
- brain
- *activation = inhibition of norepi release → inhibition of SNS = ↓BP/HR/↓CNS activity
postsynaptic
- coronaries
- CNS
- activation causes constriction, sedation, analgesia
Where are B1 found?
myocardium SA node vent-conduction system coronaries kidney
What does activation of B1 cause?
- increase inotropy
- increase chronotropy
- ↑myocardial conduction - velocity
- coronary relaxation
- renin release
Where are B2 receptors found?
smooth muscle of vasculature, bronchial, uterus
- smooth muscle of the skin
- myocardium
- coronaries
- kidneys
- GI tract
What do B2 receptors do when activated?
vasodilation
- bronchodilation
- uterine relaxation
- gluconeogenesis
- insulin release
- k uptake by the cells
Is ephedrine a direct or indirect acting?
both
Is phenylephrine a direct or indirect acting agent?
direct
in the the treatment of HTN, what medications target HR?
2
- beta blockers
2. calcium channel blockers
in the treatment of HTN, what medications target contractility?
(2)
- beta-blockers
2. calcium channel blockers
in the treatment of HTN, what medications target venous tone?
(4)
- a1 antagonists
- ACEi
- ARB
- Nitroprusside
in the treatment of HTN, what medications target Na/H2O retention?
- diuretics
- ACEi
- ARB
in the treatment of HTN, what medications target the direct innervation of vascular smooth muscle cells to decrease SVR?
- a1 antagonists
2. a2 agonists
in the treatment of HTN, what medications target circulating regulators to decrease SVR?
a1 antagonists
a2 agonists
ACEi
ARB
in the treatment of HTN, what medications target local regulators to decrease SVR?
- endothelin antagonists
- nitroprusside
- ACEi
- ARB
in the treatment of HTN, what medications target local regulators to decrease SVR?
- endothelin antagonists
- nitroprusside
- ACEi
- ARB
What are the 2 biggest cardiovascular effects of anesthetics?
- decreased SVR = decreased BP
2. depressed myocardial contractility
What are 4 types of receptors located in the peripheral nervous system?
- alpha
- beta
- nicotinic
- muscarinic
Stimulation of beta receptor results in activation of
adenyl cyclase →
↑cAMP
Increased cAMP from beta receptor activation causes..
↑ kinase activation & phosphorylation
B1,2,3 receptors are what kind of GPCR?
Gs
In the physiological response of Beta receptors, increased cAMP results in…
relaxation of smooth muscle & stimulation of cardiac contractility
What are the second messengers of a1 activation?
PLC
IP3 & DAG
PKC & increased free Ca2+
What are the second messengers of a2 activation?
- inhibition of adenylate cyclase
- ↓cAMP
- ↑K conduction
What does ↓cAMP from a2 activation cause?
smooth muscle contraction
- K hyperpolarization
What does PLC, IP3/DAG, & PKC/↑ free Ca2+ from a1 activation cause?
smooth muscle vasoconstriction
a2 is excitatory or inhibitory?
inhibitory
a1 is excitatory or inhibitory?
excitatory
↑Ca++ → calmodulin activation → ↑actin/myosin interaction → sm muscle contraction
a2 is excitatory or inhibitory?
inhibitory
↓cAMP → ↓norepinephrine release
In the treatment of HTN, what 4 classes of drugs targets the SNS?
- B-antagonists
- a1 antagonists
- mixed a/B antagonists
- centrally acting a2 agonists
In the treatment of HTN, what 3 classes of drugs target the RAAS
- ACEi
- ARB
- Diuretics
In the treatment of HTN, what classes of drugs target endothelium derived mediator and/or ion channel modulators?
- direct vasodilators (nitroprusside, hydralazine)
- calcium channel antagonists
- potassium channel opener
What is a normal BP?
120/80
What is the treatment threshold for those <60yr
or
>60yr with renal dz or diabetes?
140/90 or greater
What is the treatment threshold for those >60yr w/o DM or renal dz?
150/90 or greater
What is the first line therapy for HTN treament?
thiazide diuretic UNLESS there is a “compelling indication”
Why do most patients require at least 2 medications to reach their BP goal?
physiological compensations
What is the threshold for a hypertensive URGENCY?
DBP >120 with evidence of
progressive end organ DAMAGE
What is the goal when a patient has a hypertensive urgency? & what medication is used?
goal, decrease DBP to 100-105 w/n 24 hours
Clonidine
What is the threshold for a hypertensive CRISIS?
DBP >120 with evidence of end organ FAILURE
What is the goal when a patient has a hypertensive CRISIS?
decrease DBP 100-105 ASAP
What 4 medications can be used to treat a hypertensive crisis?
- Nitroprusside
- Nitroglycerin
- Labetalol
- Fenoldapam
What are the three competitive alpha antagonists?
Phentolamine, Prazosin, Yohimibine
What is an alpha antagonist that covalently binds and is difficult to overcome?
phenoxybenzamine
When must you give an a antagonist?
BEFORE you B-block a
pheochromocytoma or local anesthetic toxicity
What are 2 non-selective alpha antagonists?
phenoxybenzamine
phentolamine
What are 5 a1 selective antagonists?
prazosin terazosin doxazosin aifuzosin tamsulosin
What is 1 a2 selective antagonist?
yohimbine
What are 5 non-selective FIRST generation beta antagonists?
Nadolol Penbutolol Pindolol Propranolol Timolol
What are 5 B1 selective beta antagonists?
acebutolol atenolol bisoprolol esmolol metoprolol
What are 4 non-selective THIRD generation beta antagonists?
Carteolol
Carvedilol
Bucindolol
Labetolol
What are 3 B1 selective THIRD generation beta antagonists?
betaxolol
caliprolol
nebivolol
What are the mixed a and B antagonists?
labetalol
carvedilol
