Adrenergic drugs Flashcards
What do adrenergic drugs mimic
Catecholamines like Norepinephrine, Epinephrine and dopamine
Types of adrenergic receptors
A adrenergic receptor, B adrenergic receptor, and Dopaminergic receptors
Where are A1 adrenergic receptors located
Located on the postsynaptic effector cells (the cell, muscle or organ the nerve stimulates)
Where is A2 adrenergic receptors located
Located on presynaptic nerve terminals (stimulates the effector cells and control the release of NT)
What do A adrenergic agonist do
Causes Vasocontraction and CNS stimulation
Where are B adrenergic cells located
All are on postsynaptic effector cells
Where are B1 adrenergic receptors located
Located on the heart (B1, 1 heart)
Where are the B2 adrenergic receptors located
Smooth muscles of the Bronchioles, arterioles and visceral organs (B2, 2 for 2 lungs)
What do Adrenergic Agonists do
Bronchial, GI and uterine smooth muscle relaxation, glycogenolysis and cardiac stimulation
What do dopaminergic receptors do
cause dilation of the renal, mesenteric, coronary, cerebral blood vessels promoting blood flow.
What do A1 receptors on the the cardiovascular blood vessels do
Constriction
What do B1 receptors do on the cardiac muscle do
Increase contractility
What do b2 receptors on the the cardiovascular blood vessels do
Dilation
What do B1 on the AV node do
Increase heart rate
What does B1 do on the SA node
Increase heart rate
What do B2 receptors do on the GI muscle
Decrease motility and relaxation of the smooth muscle
What do the A1 receptors on the sphincter do in the GI
constriction
What does the A1 receptors do on the bladder
Contraction of the sphincter
What does A1 receptors do to the penis
Cause ejactulation
What does the A1 receptor do to the uterus
Contraction
What does the B2 receptor do to the uterus
relaxation
What does the B2 receptor do to the bronchial muscle
Dilation of relaxation of smooth muscles
What does the B2 receptors do to the liver
Glycogenolysis
What does the B2 receptors do to the liver
increase renin secretion
What does A1 receptors do to the pupillary muscle
dilation of the pupil
MOA of direct acting sympathomimetic
Binds directly to the receptor and causes a response
MOA of indirect acting sympthomimetic
Cause the release of catecholamine from the storage site. They then bind to receptors causes a reaction
MOA of mixed acting sympathomimetic
Stimulated the receptor by binding to it causing the release of stored NT
Drug effects of A adrenergic receptors on smooth muscle
- Vasoconstriction of blood vessels
- Relaxation of GI smooth muscles, decreasing motility
- Constriction of the bladder sphincter
- Contraction of uterus
- Male ejactulation
- Contraction of pupillary muscles of the eye
Drug effects of B1 adrenergic receptors on myocardium, atrioventricular (AV) node, and sinoatrial node results in cardiac stimulation.
- Increase force of contraction (positive inotropic)
- Increase heart rate (positive chronotropic)
- Increase conduction through AV node (positive dromotropic)
Drug effects of B2 adrenergic receptors
- Bronchodilation
- Uterine relaxation
- Increased renin secretion in the kidneys
- Relaxation of GI smooth muscles (decreased motility)
Indications of B2
Asthma and bronchitis (any need to dilate the bronchioles)
Indications of A1
Nasal congestion or any need for constriction of dilated arterioles
Like phenylephrine hydrochloride
What is the relief of conjunctival congestion
A adrenergic receptors ( phenylephrine hydrochloride, epinephrine )
Type of drug to reduce intraocular pressure and dilation of pupils (treatment of open angle glaucoma)
α-Adrenergic receptors
vasoactive sympathomimetics AKA…
pressors, inotropes or cardioselective sympathomimetics
Uses for cardioselective sympathomimetics
Supports the heart during cardiac failure or shock. Affects A and B-receptors
What is Dobutamine
Selective vasoactive B1-adrenergic drug
What is Dobutamine used for
Increase cardiac output by increasing contractility, Which increases stroke volume, especially in patients with heart failure.
What is Epinephrine
Endogenous vasoactive catecholamine that acts on both a and B adrenergic recepotrs
What is Epinephrine used for
Used for advanced cardiac life support (vasocontraction)
What is norepinephrine
Simulates B Adrenergic effects on the heart (B1-adnergic receptors. Does not stimulate B2 adrenergic receptors of the lungs
What does norepinephrine treat
Hypotension and shock
What is phenylephrine
Works On A adrenergic receptors
What does phenylephrine used for
used primarily for the short term treatment to raise blood pressure in patients who are in shock, Vasocontraction in regional anaesthesia
A adrenergic adverse effects
- CNS
Headache, restlessness, excitement, insomnia, euphoria - Cardiovascular
Palpitations (dysrhythmias), tachycardia, vasoconstriction, hypertension - Other
Loss of appetite, dry mouth, nausea, vomiting, taste changes (rare)
B adrenergic adverse effects
- CNS
Mild tremors, headache, nervousness, dizziness, insomnia, euphoria - Cardiovascular
Chest pain, increased heart rate, palpitations (dysrhythmias), hypertension, vasoconstriction - Other
Sweating, nausea, vomiting, muscle cramps
Interactions of adrenergic drugs
- Anesthesia drugs
- Digoxin
- MAOIs
- Tricyclic antidepressants (hypertensive crisis)
Antihistamines (increased adrenergic effects) - Thyroid preparations
