(1) Autonomic Drugs: Sympathetic (2.1-2.4) Flashcards
What effect does α1 stimulation have on the vasculature?
(1) Constrict arterioles ⇒ ↑ TPR
(2) Constrict veins ⇒ ↑ Preload
Which adrenergic receptor leads to urinary retention?
α1
Which adrenergic receptor inhibits the release of insulin?
α2
Which adrenergic receptor inhibits lipolysis?
α2
Which adrenergic receptor inhibits the production of aqueous humor?
α2
Indication: Brimonidine
Open-angle glaucoma
Which adrenergic receptor stimulates renin release?
β1
Which adrenergic receptor can cause hypokalemia?
β2
What effect does Phenylephrine have on Psys, Pdia, and MAP?
(1) Psys : ↑
(2) Pdia : ↑
(3) MAP: ↑
What is the receptor specificity of Norepinephrine?
α > β
What is the receptor specificity of Dobutamine?
β1 > β2
What effect does Dobutamine have on Psys, Pdia, and MAP?
(1) Psys : ↑
(2) Pdia : ↓
(3) MAP: ↔
Which sympathomimetic is used for cardiogenic shock?
Dobutamine
What effect does Isoprotenerol have on Psys, Pdia, and MAP?
(1) Psys : ↔
(2) Pdia : ↓
(3) MAP: ↓
Indications (2) : Terbutaline
(1) Asthma
(2) Preventing premature labor
What is the receptor specificity of Epinephrine?
(1) Low doses: β > α
(2) High doses: α predominant
Which adrenergic receptor stimulates lipolysis?
β2
Which adrenergic receptor stimulates the release of insulin?
β2
Which adrenergic receptor stimulates the production of aqueous humor?
β2
What effect does Norepinephrine have on Psys, Pdia, and MAP?
(1) Psys : ↑
(2) Pdia : ↑
(3) MAP: ↑
What effect does Epinephrine have on Psys, Pdia, and MAP?
(1) Psys : ↑
(2) Pdia : ↓
(3) MAP: ↔ / ↑
Name 2 drugs which would be helpful in the acute management of distributive shock
(1) Phenylephrine
(2) Norepinephrine
Treatment: Anaphylactic shock
Epinephrine
(“α1 counters vasodilation, β1 improves blood flow to tissues, and β2 opens up the airways”)
What drug inhibits the conversion of tyrosine to L-DOPA?
Metyrosine
MOA: Cocaine
Inhibits NET and DAT
Why are β-blockers contraindicated in those on cocaine?
⇒ Unopposed α stimulation
MOA: Atomoxetine
NET inhibitor
(NET = norepinephrine transporter)
MOA: Reserpine
Inhibits VMAT
(“V” mat: vesicular monoamine transporter (VMAT))
What type of G-proteins are D1 and D2 receptors?
(1) D1: Gs
(2) D2: Gi
What receptor mediates the effects of a low dose of dopamine?
Low dose: D1 receptors ⇒ ↑ Renal blood flow
What receptor mediates the effects of a medium dose of dopamine?
Medium dose: β1 receptor⇒ ↑ Contractility/HR
What receptor mediates the effects of a high dose of dopamine?
High dose: α1 receptor⇒ ↑ TPR
Where does the conversion of dopamine into norepinephrine occur?
Within the synaptic vesicle
MOA: Amphetamine
↑ Endogenous release of NE/DA
Indications (3) : Clonidine
(1) Hypertension
(2) ADHD
(3) Tourettes
Treatment: Gestational hypertension
α-methyldopa
Adverse Effect: α-methyldopa
Drug-induced lupus
(Also Coombs-positive hemolytic anemia)
Indication: Tizanidine
Muscle relaxant
MOA: Phentolamine
REVERSIBLE α1 and α2 antagonist
MOA: Phenoxybenzamine
Irreversibly inhibits α1 and α2
What drug should be used to treat cocaine toxicity?
Phentolamine
Name a drug that provides symptomatic relief for BPH
Terazosin
What sympatholytic is used to treat PTSD?
Prazosin
What adrenergic receptor does Mirtazapine inhibit?
α2
MOA: Clonidine
α2 agonist
Adverse Effects (2) : α1 antagonists
(1) Orthostatic hypotension
(2) ⇒ Reflex tachycardia
Suffix: α1 antagonist
“-osin”
What type of sympatholytic are useful in chronic stable angina?
β blockers
What are the primary indications for the cardio-selective β-blockers?
(1) CHF
(2) MI
Name 2 non-selective β + α1 blockers
(1) Carvedilol
(2) Labetalol
* (Notice this class differs from the “-olol” suffix)*
What β-blocker is used to treat hypertension in pregnancy?
Labetalol
Which class of sympatholytic is useful in hypertrophic obstructive cardiomyopathy?
β-blockers
(↓ Ventricle volume ∝ ↑ Outflow resistance ∴ β-blockers mediated ↓ in stroke volume helps with symptoms)
Indications - Non-cardiac (4) : β-blockers
(1) Migraines
(2) Thyroid storm
(3) Tremor
(4) Glaucoma
What drug is a selective β1-blocker with partial agonist activity?
Acebutolol
What drug is a non-selective β-blocker with partial agonist activity?
Pindolol
Which β-blockers are contraindicated in heart failure?
Partial agonists
Treatment: β-blocker poisoning
Glucagon
(+ atropine)
What is a topical β-blocker useful in treating glaucoma?
Timolol
What new EKG findings may present when on β-blockers?
Heart block
How can you identify a β1 selective antagonist?
Name start with A-BEAM
(Note: Nevbivolol is the exception. However, it’s memorable as it also induces NO release)
Name 2 reasons β-blockers are helpful in CHF
(1) Prevents remodeling (due to excess catecholamines)
(2) ↓ Renin (and ∴ prevents fluid overload and AngII mediated remodeling)
Adverse Effects (3) : β-blockers
(1) ⇒ Heart block
(2) Exacerbate asthma
(3) Impotence