28 Questions
What type of receptors does epinephrine interact with?
Both alpha and beta receptors
What is the primary therapeutic use of norepinephrine?
Treating acute hypotension in unstable patients
What is the effect of dopamine on renal blood flow?
Increases renal blood flow
Which of the following is a side effect of epinephrine?
All of the above
What is the difference in the effects of low-dose and high-dose epinephrine?
Low-dose epinephrine stimulates beta receptors, while high-dose epinephrine stimulates alpha receptors
What is the therapeutic use of isoproterenol?
Managing bronchial asthma
What is the primary action of dopamine on the cardiovascular system?
Positive inotropy and chronotropy
What is the therapeutic use of fenoldopam?
Rapid vasodilation for severe hypertension
What is the difference between dopamine 1 and dopamine 2 receptors?
Dopamine 1 receptors cause vasodilation, while dopamine 2 receptors inhibit norepinephrine release
What is the therapeutic use of dobutamine?
Managing heart failure
What is the mechanism of action of cocaine?
Blockade of Na+/K+ pump required for reuptake of norepinephrine
What is the effect of phenoxybenzamine on blood pressure?
Decreases blood pressure
What is the effect of β blockers on cardiac output?
Decrease cardiac output
What is the mechanism of action of quinazoline-based drugs?
Blockade of alpha-1 adrenergic receptors
What is the mechanism of β blockers in reducing renin secretion?
Block β1 receptors in the kidneys
What is the primary use of prazosin?
Treatment of hypertension
What is the effect of phentolamine on the pupil?
Miosis
Which of the following β blockers is a hybrid antihypertensive drug?
Labetalol
What is the mechanism of action of reserpine?
Depletion of biogenic amines from central and peripheral synapses
What is the effect of β blockers with ISA on the heart rate?
No effect on heart rate
What is the effect of guanethidine on blood pressure?
Decreases blood pressure
What is the clinical use of β blockers in relation to myocardial infarction?
Prophylaxis of arrhythmias
Which of the following β blockers is cardio-selective?
Metoprolol
What is the primary adverse effect of guanethidine?
Orthostatic hypotension
What is the effect of tamsulosin on urinary flow?
Decreases resistance to urinary flow
What is the effect of β blockers on automaticity of the sinoatrial (SA) node?
Decrease automaticity of the SA node
Which generation of β blockers includes non-selective β blockers?
1st generation
What is the first dose phenomenon associated with quinazoline-based drugs?
Orthostatic hypotension and reflex tachycardia
Study Notes
Adrenergic Agonists
- Act on receptors stimulated by epinephrine and norepinephrine
- Mediate major effects through β receptors
- β1: Increase myocardial contractility, heart rate, and lipolysis
- β2: Vasodilation, bronchodilation, relaxation of uterine smooth muscle
- β3: Lipolysis in adipose tissue
Direct Acting Adrenergic Agonists
- Endogenous/Natural Occurring: Epinephrine, Norepinephrine, Dopamine
- Synthetic: Dobutamine, Isoproterenol
- Epinephrine: interacts with alpha and beta receptors, depending on dose
- Low dose: beta receptor activity predominates (vasodilation)
- High dose: alpha receptor activity predominates (vasoconstriction)
Actions of Epinephrine
- Cardiovascular system: (+) inotropic and chronotropic effects, peripheral vasoconstriction and vasodilation
- Respiratory system: Bronchodilation
- Liver: Glycogenolysis
- Pancreas: Insulin secretion
- Adipose tissue: Lipolysis
Therapeutic Use of Epinephrine
- Bronchospasm
- Anaphylactic shock
- Glaucoma
- Anesthetics
Norepinephrine
- Affects mostly alpha receptors
- Actions:
- Cardiovascular: vasoconstriction
- Therapeutic use:
- Acute hypotension
- Atropine pre-treatment
- Cardiac arrest
Isoproterenol
- Non-selective β1 and β2 agonist
- Actions:
- Cardiovascular: (+) inotropic and chronotropic effects, decreased peripheral resistance
- Pulmonary: Bronchodilation
- Therapeutic use: Bronchial Asthma
Dopamine
- Acts on A1 and B1 receptors
- D1 receptors: vasodilation, especially in renal, coronary, mesenteric, and cerebral vascular beds
- D2 receptors: inhibit norepinephrine release
- Actions:
- Cardiovascular: (+) inotropic and chronotropic effects, vasoconstriction, and vasodilation
- Therapeutic use: Primarily used for cardiogenic shock and acute heart failure
Other Direct Acting Agents
- Fenoldopam: IV, D1, and A2 receptors, rapid vasodilation for severe hypertension
- Phenylephrine: A1, nasal decongestant
- Dobutamine: B1, (+) inotropic effect, congestive heart failure
- Clonidine: A2, essential hypertension, CNS action
Indirect Acting Adrenergic Agents
- Amphetamines: release norepinephrine from presynaptic terminals, central stimulation
- Tyramine: increases norepinephrine release from presynaptic terminals
- Cocaine: local anesthetic, blocks Na+/K+ pump, enhances norepinephrine activity
- Mixed-Action Adrenergic Agents:
- Ephedrine: enhances contractility, Myasthenia Gravis
- Metaraminol: shock treatment, alternative to norepinephrine
Adrenergic Agonists Side Effects
- Arrhythmias
- Headache
- Hyperactivity
- Insomnia
- Nausea
- Tremors
This quiz covers the effects of adrenergic agonist drugs on receptors stimulated by epinephrine and norepinephrine, including vasodilation, tachycardia, and bronchodilation.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
