Adrenergic Drugs Flashcards
What are adrenergic drugs?
Drugs that simulate the sympathetic nervous system (SNS)
What SNS neurotransmitters do adrenergic drugs mimic?
Norepinephrine
Epinephrine
Dopamine
What are a1-adrenergic receptors?
Located on postsynaptic effector cells
What are a2-adrenergic receptors?
Located on presynaptic nerve terminals
Control the release of neurotransmitters
What are the a-adrenergic agonist responses?
Vasoconstriction
CNS stimulation
What’s the difference between b1 and b2 adrenergic receptors?
B1: Heart
B2: Lungs
What are the b-adrenergic agonist responses?
Bronchial, GI and Uterine smooth muscle relaxation
Glycogenolysis
Cardiac stimulation
What blood vessels do the dopaminergic receptors dilate ?
Renal
Mesenteric
Coronary
Cerebral
What is the MOA of indirect-acting sympathomimetics?
Causes release of catecholamine in nerve endings
Catecholamine binds to receptors and causes a physiological response
What is the MOA of mixed-acting sympathomimetic?
Direct and indirect acting actions
What are the indications of adrenergic drugs and which receptors would they affect ?
Asthma and bronchitis: b2-adrenergic receptors
Nasal congestion: a1-adrenergic receptors
Conjunctival congestion: a-adrenergic receptors
Dilation of pupils and reduction of intraocular pressure: a-adrenergic receptors
What are vasoactive sympathomimetics and what are they AKA?
AKA: Pressors, inotropes
Used to support the heart during cardiac failure or shock
Name 5 vasoactive sympathomimetics
Dobutamine
Dopamine
Epinephrine
Norepinephrine
Phenylephrine
What is dobutamine HCL? (form and MOA)
Stimulates b1- receptors on heart muscle increased cardiac output by increasing contractility, which increased stroke volume.
IV drug via continuous infusion
What is dopamine HCL? (difference between dosages)
Low dosages: Dilate blood vessels in the brain, heart, kidneys and mesentery, which increases blood flow to these areas
Higher rates: Improved cardiac contractility and output
Highest doses: vasoconstriction
What is epinephrine?
Acts directly on both the a and b-adrenergic receptors of tissues innervated by the SNS
Administered in emergency situations
What is norepinephrine?
Stimulates a-adrenergic receptors
Causes vasoconstriction
Treatment of hypotension and shock
What is phenylephrine?
Used primarily for short-term treatment to raise BP
Control of supraventricular tachycardias
Vasoconstriction in regional anaesthesia
What are the CNS, cardiovascular and other AE of a-adrenergic drugs?
CNS: Headache, restlessness, excitement, insomnia, euphoria
CV: Palpitations, tachycardia, vasoconstriction, HTN
Other: Loss of appetite, dry mouth, nausea, vomiting, taste changes
What are the CNS, cardiovascular and other AE of b-adrenergic drugs?
CNS: Mild tremors, headache, nervousness, dizziness, insomnia, euphoria
CV: Chest pain, increased HR, palpitations, HTN, vasoconstriction
Other: Sweating, nausea, vomiting, cramps
What are the interactions of adrenergic drugs?
Anaesthetic drugs
Digoxin
Tricyclic antidepressants (HTN)
MAOIs (HTN)
Antihistamines
Thyroid drugs
What is a consideration regarding salmeterol xinafoate?
Indicated for the prevention of bronchospasms, not management of acute symptoms
