Adrenergics Flashcards
1
Q
Adrenergic agonist
- Alpha and beta
- Increase heart rate and contractility–> increase cardiac output and oxygen demand of heart
- Vascular: decreased cutaneous, visceral, and renal blood flow using alpha1 receptors–> raises blood pressure, but increases skeletal muscle blood flow using beta2
- Bronchodilation by beta2 especially high if bronchioles are pre-constricted: anaphylaxis, asthma
- Topical hemostatic agent = limits bleeding
A
Epinephrine
2
Q
Adrenergic agonist
- Alpha and beta
- Doesn’t stimulate beta2 receptors much–> no bronchodilation
- More pronounced vasoconstriction(no vasodilation in skeletal muscle)–> increase in blood pressure
- Limited use: cardiovascular support to maintain BP during shock
A
Norepinephrine
3
Q
Adrenergic agonist
- Alpha and beta
- Low dose–> stimulates D1 receptors–> vasodilation
- Increased renal blood flow and sodium excretion
- Stimulates cardiac beta1 receptors–> increased heart rate
- High dose–> stimulate vascular alpha1 receptors–> vasoconstriction–> decreased renal blood flow and sodium excretion
A
Dopamine
4
Q
Adrenergic agonist
- Complex agonist for B1> B2 and a1
- Cardiovascular = increased contractility via B1 with minimal change in heart rate
- Minimal change in heart rate
- Used during cardiac failure to increase BP
A
Dobutamine
5
Q
Adrenergic agonist
- Selective for B2–> bronchodilation
- Use for asthma, heaves in horses
- Beta receptors down regulate if continuously stimulated–> loss of efficacy
- Minimize with proper dose and dosing schedule
A
Albuterol and Clenbuterol
6
Q
Adrenergic agonist
- Selective a1
- Decongestant, vasopressor
A
Phenylephrine
7
Q
Adrenergic agonist
- Selective a2—> Effect primarily in CNS and pre-synaptic neurons = sedation, analgesia, decreased sympathetic outflow from brain
- Relatively high safety profile
- Decreases blood pressure over all, may have initial increase in BP first
A
(Dex)Medetomidine and xylazine
8
Q
Adrenergic antagonist
- Non-competitive = covalently binds receptors, irreverseable
- Non-selective
- Reduce urethral sphincter tone
A
Phenoxybenzamine
9
Q
Adrenergic antagonist
- Competitive
- Non-selective alpha
- Reverseable
A
Phentolamine
10
Q
Adrenergic antagonist
- Competitive
- Non-selective Beta–> can cause bronchoconstriction acting on B2
- Decreases cardiac output
A
Propanolol
11
Q
Adrenergic antagonist
- Competitive
- Non-selective Beta–> can cause bronchoconstriction acting on B2
- Ocular use to decrease aqueous humor production during glaucoma
A
Timolol
12
Q
Adrenergic antagonist
- Competitive
- Selective a1
- Vasodilation–> decreased BP
- Relax arteries and veins
- Decreased peripheral resistance and venous return–> Decreased after-load and pre-load
- Used as antihypertensive and in congestive hear failure
- Decreased peripheral resistance and venous return–> Decreased after-load and pre-load
A
Prasosin
13
Q
Adrenergic antagonist
- Competitive
- Selective a2–> Less sedation, increased sympathetic outflow from brain, increased norepinephrine release
- Used to reverse medetomidine using 5x dose of medetomidine
- Rapidly reverseable, with minimal risk for relapse into sedation: longer halflife and greater amount than medetomadine
- Increases sympathetic activity: can exacerbate cardiac or respiratory disease
A
Atipamezole
14
Q
Adrenergic antagonist
- Competitive
- Selective B1–> Decrease cardiac output–> decrease cardiac oxygen demand and BP, and decreases cardiac arhythmias
A
Atenolol
15
Q
Adrenergic antagonist
- Competitive
- Selective for B1 and a1
- Used to treat congestive heart failure and valvular disease
- Antioxidant properties
- Counteract anticholenergic tachycardia: ex from atropine
A
Carvedilol
