Adrenomimetic Drugs Flashcards
What do adrenergic drugs modulate?
Adrenergic transmission and primarily control the function of sympathetic nervous system
Drugs activating adrenergic transmission (adrenomimetics or sympathomimetics) mimic or promote the effects of what?
Norepinephrine/epinephrine/dopamine at adrenergic receptors in the sympathetic NS
Drugs inhibiting adrenergic transmission (sympatholytics or anti-adrenergic drugs) prevent the effects of what?
Norepinephrine/epinephrine/dopamine at adrenergic receptors in the sympathetic NS
What are the types of a1 receptors?
a1A, a1B, a1D
Which G protein is associated with a1 receptors?
Gq
What are the effects of Gq binding to a1 receptors?
Increase IP3 and DAG common to all
What are the types of a2 receptors?
a2A, a2B, a2C
Which G protein is associated with a2 receptors?
Gi
What are the effects of Gi binding to a2 receptors?
Decrease cAMP
What are the types of B receptors?
B1, B2, B3
Which G protein is associated with B receptors?
Gs which increases cAMP
What are the types of dopamine receptors?
D1 and D2
Which G protein is associated with D1 receptors?
Gs which increases cAMP
Which G protein is associated with D2 receptors?
Gi which decreases cAMP
Review
Signal transduction slides
Direct acting adrenergic drugs produce their effects via what?
Direct interaction with adrenergic receptors
Ex. Adrenergic receptor agonists or antagonists
Indirect acting adrenergic drugs produce their effects by doing what?
Increased or reducing the concentration of NE at target receptors
Work by altering neurotransmitter concentrations at target site
What are the categories of direct adrenomimetics?
Alpha agonists, beta agonists, mixed alpha and beta agonists
What are examples of alpha agonists?
Phenylephrine (a1) and clonidine (a2)
What are examples of mixed alpha and beta agonists?
NE (a1 and a2 equally, B1 > B2) and epinephrine (all receptors equally)
What are examples of beta agonists?
Dobutamine (B1), isoproterenol (B1 and B2 equally), albuterol (B2)
Where are alpha-1 receptors found?
Most vascular smooth muscle (Innervated), pupillary dilator muscle, prostate and heart
What are the actions of a1 receptors?
Vascular smooth muscle contraction
Contraction of pupillary dilator muscle (dilates pupil)
Contraction of the prostate
Increases force of contraction in the heart
Where are a2 receptors found?
Neurons, platelets, adrenergic and cholinergic nerve terminals, some vascular smooth muscle and fat cells
What are the actions of a2 receptors?
Modulates transmitter release from neurons
Platelet aggregation
Inhibits transmitter release from adrenergic and cholinergic nerve terminals
Contraction of some vascular smooth muscle
Inhibits lipolysis
Where are B1 receptors found?
Heart and juxtaglomerular cells
What are the actions of B1 receptors?
Increases force and rate of heart contraction
Increases renin release
Where are B2 receptors found?
Respiratory, urine, and vascular smooth muscle
Skeletal muscle
Human liver
What are the actions of B2 receptors?
Promotes smooth muscle relaxation
Promotes K+ uptake in skeletal muscle
Activates glycogenolysis and gluconeogenesis
Where are B3 receptors found?
Bladder and fat cells
What are the actions of B3 receptors?
Relaxes detrusor muscle
Activates lipolysis
Where are D1 receptors found?
Smooth muscle where it dilates renal blood vessels
Where are D2 receptors found?
Nerve endings where it modulates transmitter release
Which adrenomimetic drug can be used for hypotensive emergencies such as hemorrhagic shock, overdose of anti-hypertensives or CNS depressants?
NE and phenylephrine
Which adrenomimetic drug can be used for Chronic hypotension?
Ephedrine
Which adrenomimetic drug can be used for cardiogenic shock?
Dobutamine
Which adrenomimetic drug can be used for heart failure?
Short term use of dobutamine in acute HF
Which adrenomimetic drug can be used for HTN?
Alpha-2 agonists for the long term Tx
Which adrenomimetic drug can be used for emergency the arepa for complete AV block and cardiac arrest?
Epinephrine and isoproterenol
Which adrenomimetic drug can be used for depression?
Phenelzine and Selegiline
Which adrenomimetic drug can be used for narcolepsy?
Amphetamines and methylphenidate
Which adrenomimetic drug can be used for ADHD?
Methylphenidate
Which adrenomimetic drug can be used for obesity?
Ephedrine
Amphetamines
Which adrenomimetic drug can be used for bronchial asthma?
Albuterol
Which adrenomimetic drug can be used for decongestion of mucous membranes?
Phenylephrine and ephedrine
Which adrenomimetic drug can be used for anaphylaxis?
Epinephrine (effective at both respiratory (bronchospasm) and cardiovascular (severe hypotension, cardiac depression) components
Which adrenomimetic drug can be used for ophthalmic applications?
Examination of retina - induction of mydriasis —> phenylephrine
Glaucoma —> alpha 2 selective agonists
Which adrenomimetic drug can be used for stress urinary incontinence?
Ephedrine
