objective 2.2 (pt.1) (1) Flashcards
drugs that stimulate the SNS
adrenergic drugs
what are the adrenergic drug characteristics?
norepinephrine
epinphrine
dopamine
located throughout the body
are receptors for the sympathetic neurotransmitters
adrenergic receptors
what are the adrenergic receptors?
α-Adrenergic receptors
ß-Adrenergic receptors
Dopaminergic receptors
what are the two groups of α-Adrenergic receptors?
α1 - and α2 -receptors
Located on postsynaptic effector cells (the cell, muscle, or organ the nerve stimulates)
α1 -Adrenergic receptors
Located on presynaptic nerve terminals (the nerve that stimulates the effector cells)
α2 -Adrenergic receptors
Vasoconstriction & Central nervous system (CNS) stimulation
α-Adrenergic Agonist Responses
all are located on the postsynaptic effector cells
ꞵ-Adregergic receptors
what are the types of ꞵ-Adregergic receptors?
ß1 -Adrenergic receptors
ß2 -Adrenergic receptors
located primarily in the heart
ß1 -Adrenergic receptors
located in smooth muscle of the bronchioles, arterioles, and visceral organs
ß2 -Adrenergic receptors
Binds directly to the receptor and causes a physiological response
direct-acting sympathomimetic
Causes release of catecholamine from storage sites (vesicles) in nerve endings
Catecholamine then binds to receptors and causes a physiological response.
indirect-acting sympathomimetic
Directly stimulates the receptor by binding to it
Indirectly stimulates the receptor by causing the release of stored neurotransmitters from vesicles in the nerve endings
mixed-acting sympathomimetic
what does stimulation of α-adrenergic receptors on smooth muscles results in?
Vasoconstriction of blood vessels; Relaxation of GI smooth muscles (decreased motility); Constriction of bladder sphincter; Contraction of uterus; Male ejaculation; Contraction of pupillary muscles of the eye (dilated pupils)
what does stimulation of ß1 -adrenergic receptors on the myocardium, atrioventricular (AV) node, and sinoatrial node (SA) result in?
Increased force of contraction; Increased heart rate; Increased conduction through AV node
what does stimulation of ß2 -adrenergic receptors on the airways result in?
bronchodilation (relaxation of the bronchi).
Other effects of ß2 -adrenergic stimulation: Uterine relaxation; Glycogenolysis in the liver; Increased renin secretion in the kidneys; Relaxation of GI smooth muscles (decreased motility)
drugs that stimulate ß2 -adrenergic receptors of bronchial smooth muscles, causing relaxation, resulting in bronchodilation
bronchodilators
how do we treat asthma and bronchitis?
bronchodilators
what are common bronchodilators?
formoterol fumurate dihydrate, salbutamol, salmeterol, xinafoate, and terbutaline sulphate.
how do we treat nasal congestion?
Intranasal (topical) application
α1 -Adrenergic receptors
causes constriction of dilated arterioles and reduction of nasal blood flow, thus decreasing congestion.
intranasal (topical) application
what are examples of intranasal (topical) application?
oxymetazoline hydrochloride and phenylephrine hydrochloride
what can α-Adrenergic receptors also be used to treat?
open-angle glaucoma
temporary relief of conjunctival congestion
Also called cardioselective sympathomimetics.
Used to support the heart during cardiac failure or shock; various α- and ß-receptors affected.
vasoactive sympathomimetics
what are examples of vasoactive sympathomimetics?
Dobutamine
Dopamine
Midodrine
Epinephrine
Phenylephrine
Norepinephrine
Stimulates ß1 -receptors on heart muscle (myocardium); increases cardiac output by increasing contractility (positive inotropy), which increases stroke volume, especially in patients with heart failure.
Intravenous drug; given by continuous infusion
dobutamine hydrochloride
Naturally occurring catecholamine neurotransmitter, Potent dopaminergic as well as ß1 - and α1 -adrenergic receptor activity, Low dosages: can dilate blood vessels in the brain, heart, kidneys, and mesentery, which increases blood flow to these areas (dopaminergic receptor activity), Higher infusion rates: improve cardiac contractility and output (ß1 -adrenergic receptor activity) , Highest doses: vasoconstriction (α1 -adrenergic receptor activity)
dopamine hydrochloride
Acts directly on both the α- and ß- receptors of tissues , Administered in emergency situations, One of the primary vasoactive drugs used in many advanced cardiac life support protocols.
epinephrine hydrochloride
Stimulates α-adrenergic receptors, Causes vasoconstriction, Direct-stimulating ß-adrenergic effects on the heart (ß1 -adrenergic receptors), No stimulation to ß2 -adrenergic receptors of the lung, Treatment of hypotension and shock, Administered by continuous infusion
norepinephrine betartrate
what are the AE of α-Adrenergic drugs?
CNS: Headache, restlessness, excitement, insomnia, euphoria
Cardiovascular: Palpitations (dysrhythmias), tachycardia, vasoconstriction, hypertension
Other: Loss of appetite, dry mouth, nausea, vomiting, taste changes (rare)
what are the AE of ß-Adrenergic drugs?
CNS: Mild tremors, headache, nervousness, dizziness, insomnia, euphoria
Cardiovascular: Chest pain, increased heart rate, palpitations (dysrhythmias), hypertension, vasoconstriction
Other: Sweating, nausea, vomiting, muscle cramps
what are the interactions of adrenergic drugs?
Anaesthetic drugs
Digoxin
Tricyclic antidepressants
Monoamine oxidase inhibitors (MAOIs)
Antihistamines
Thyroid preparations
